How many seconds are in a year?

In astronomy, the Julian year is a unit of time; it is defined as 365.25 days of exactly 86,400 seconds (SI base unit), totalling exactly 31,557,600 seconds in the Julian astronomical year.

Year

A year is the orbital period of the Earth moving in its orbit around the Sun. Due to the Earth's axial tilt, the course of a year sees the passing of the seasons, marked by change in weather, the hours of daylight, and, consequently, vegetation and soil fertility. The current year is 2022.

In temperate and subpolar regions around the planet, four seasons are generally recognized: spring, summer, autumn, and winter. In tropical and subtropical regions, several geographical sectors do not present defined seasons; but in the seasonal tropics, the annual wet and dry seasons are recognized and tracked.

A calendar year is an approximation of the number of days of the Earth's orbital period as counted in a given calendar. The Gregorian calendar, or modern calendar, presents its calendar year to be either a common year of 365 days or a leap year of 366 days, as do the Julian calendars; "see" below. For the Gregorian calendar, the average length of the calendar year (the mean year) across the complete leap cycle of 400 years is 365.2425 days. The ISO standard ISO 80000-3, Annex C, supports the symbol "a" (for Latin "annus") to represent a year of either 365 or 366 days. In English, the abbreviations "y" and "yr" are commonly used.

The word "year" is also used for periods loosely associated with, but not identical to, the calendar or astronomical year, such as the seasonal year, the fiscal year, the academic year, etc. Similarly, "year" can mean the orbital period of any planet; for example, a Martian year and a Venusian year are examples of the time a planet takes to transit one complete orbit. The term can also be used in reference to any long period or cycle, such as the Great Year.

English "year" (via West Saxon "ġēar" (), Anglian "ġēr") continues Proto-Germanic "*jǣran" ("*jē₁ran").
Cognates are German "Jahr", Old High German "jār", Old Norse "ár" and Gothic "jer", from the Proto-Indo-European noun "" "year, season". Cognates also descended from the same Proto-Indo-European noun (with variation in suffix ablaut) are Avestan "yārǝ" "year", Greek (hṓra) "year, season, period of time" (whence "hour"), Old Church Slavonic "jarŭ", and Latin "hornus" "of this year".

Latin "annus" (a 2nd declension masculine noun; "annum" is the accusative singular; "annī" is genitive singular and nominative plural; "annō" the dative and ablative singular) is from a PIE noun "", which also yielded Gothic "aþn" "year" (only the dative plural "aþnam" is attested).

Although most languages treat the word as thematic "*yeh₁r-o-", there is evidence for an original derivation with an "*-r/n" suffix, "*yeh₁-ro-". Both Indo-European words for year, "*yeh₁-ro-" and "*h₂et-no-", would then be derived from verbal roots meaning "to go, move", "*h₁ey-" and "*h₂et-", respectively (compare Vedic Sanskrit "éti" "goes", "atasi" "thou goest, wanderest").
A number of English words are derived from Latin "annus", such as annual, annuity, anniversary, etc.; "per annum" means "each year", "anno Domini" means "in the year of the Lord".

The Greek word for "year",, is cognate with Latin "vetus" "old", from the PIE word "*wetos-" "year", also preserved in this meaning in Sanskrit'"year" and'"yearling (calf)", the latter also reflected in Latin "vitulus" "bull calf", English "wether" "ram" (Old English "weðer", Gothic "wiþrus" "lamb").

In some languages, it is common to count years by referencing to one season, as in "summers", or "winters", or "harvests". Examples include Chinese 年 "year", originally 秂, an ideographic compound of a person carrying a bundle of wheat denoting "harvest". Slavic besides "godŭ" "time period; year" uses "lěto" "summer; year".

In the International System of Quantities (ISO 80000-3), the year (symbol, "a") is defined as either 365 days or 366 days.

No astronomical year has an integer number of days or lunar months, so any calendar that follows an astronomical year must have a system of intercalation such as leap years.

In the Julian calendar, the average (mean) length of a year is 365.25 days. In a non-leap year, there are 365 days, in a leap year there are 366 days. A leap year occurs every fourth year, or leap year, during which a leap day is intercalated into the month of February. The name "Leap Day" is applied to the added day.

The Revised Julian calendar, proposed in 1923 and used in some Eastern Orthodox Churches,
has 218 leap years every 900 years, for the average (mean) year length of days, close to the length of the mean tropical year, days (relative error of 9·10).
In the year 2800 CE, the Gregorian and Revised Julian calendars will begin to differ by one calendar day.

The Gregorian calendar attempts to cause the northward equinox to fall on or shortly before March 21 and hence it follows the northward equinox year, or tropical year. Because 97 out of 400 years are leap years, the mean length of the Gregorian calendar year is days; with a relative error below one ppm (8·10) relative to the current length of the mean tropical year ( days) and even closer to the current "March equinox year" of days that it aims to match. It is estimated that by the year 4000 CE, the northward equinox will fall back by one day in the Gregorian calendar, not because of this difference, but due to the slowing of the Earth's rotation and the associated lengthening of the day.

Historically, lunisolar calendars intercalated entire leap months on an observational basis.
Lunisolar calendars have mostly fallen out of use except for liturgical reasons (Hebrew calendar, various Hindu calendars).

A modern adaptation of the historical Jalali calendar, known as the Solar Hijri calendar (1925), is a purely solar calendar with an irregular pattern of leap days based on observation (or astronomical computation), aiming to place new year (Nowruz) on the day of vernal equinox (for the time zone of Tehran), as opposed to using an algorithmic system of leap years.

A calendar era assigns a cardinal number to each sequential year, using a reference point in the past as the beginning of the era.

The worldwide standard is the Anno Domini era (but the label Common Era is preferred by some). It was historically introduced in the 6th century and intended as counting years from the birth of Jesus.

The Anno Domini era is given the Latin abbreviation AD (for Anno Domini "in the year of the Lord"), or alternatively CE for "Common Era. Years before AD 1 are abbreviated BC for Before Christ or alternatively BCE for Before the Common Era.
Year numbers are based on inclusive counting, so that there is no "year zero".
In the modern alternative reckoning of Astronomical year numbering, positive numbers indicate years AD, the number 0 designates 1 BC, −1 designates 2 BC, and so on.

Financial and scientific calculations often use a 365-day calendar to simplify daily rates.

A fiscal year or financial year is a 12-month period used for calculating annual financial statements in businesses and other organizations. In many jurisdictions, regulations regarding accounting require such reports once per twelve months, but do not require that the twelve months constitute a calendar year.

For example, in Canada and India the fiscal year runs from April 1; in the United Kingdom it runs from April 1 for purposes of corporation tax and government financial statements, but from April 6 for purposes of personal taxation and payment of state benefits; in Australia it runs from July 1; while in the United States the fiscal year of the federal government runs from October 1.

An academic year is the annual period during which a student attends an educational institution. The academic year may be divided into academic terms, such as semesters or quarters. The school year in many countries starts in August or September and ends in May, June or July. In Israel the academic year begins around October or November, aligned with the second month of the Hebrew Calendar.

Some schools in the UK and USA divide the academic year into "three" roughly equal-length terms (called "trimesters" or "quarters" in the USA), roughly coinciding with autumn, winter, and spring. At some, a shortened summer session, sometimes considered part of the regular academic year, is attended by students on a voluntary or elective basis. Other schools break the year into "two" main semesters, a first (typically August through December) and a second semester (January through May). Each of these main semesters may be split in half by mid-term exams, and each of the halves is referred to as a "quarter" (or "term" in some countries). There may also be a voluntary summer session and/or a short January session.

Some other schools, including some in the United States, have "four" marking periods. Some schools in the United States, notably Boston Latin School, may divide the year into "five or more" marking periods. Some state in defense of this that there is perhaps a positive correlation between report frequency and academic achievement.

There are typically 180 days of teaching each year in schools in the US, excluding weekends and breaks, while there are 190 days for pupils in state schools in Canada, New Zealand and the United Kingdom, and 200 for pupils in Australia.

In India the academic year normally starts from June 1 and ends on May 31. Though schools start closing from mid-March, the actual academic closure is on May 31 and in Nepal it starts from July 15.

Schools and universities in Australia typically have academic years that roughly align with the calendar year (i.e., starting in February or March and ending in October to December), as the southern hemisphere experiences summer from December to February.

The Julian year, as used in astronomy and other sciences, is a time unit defined as exactly 365.25 days. This is the normal meaning of the unit "year" (symbol "a" from the Latin "annus") used in various scientific contexts. The Julian century of days and the Julian millennium of days are used in astronomical calculations. Fundamentally, expressing a time interval in Julian years is a way to precisely specify how many days (not how many "real" years), for long time intervals where stating the number of days would be unwieldy and unintuitive. By convention, the Julian year is used in the computation of the distance covered by a light-year.

In the Unified Code for Units of Measure, the symbol, "a" (without subscript), always refers to the Julian year, "a", of exactly seconds.

The SI multiplier prefixes may be applied to it to form "ka" (kiloannus), "Ma" (megaannus), etc.

Each of these three years can be loosely called an "astronomical year".

The sidereal year is the time taken for the Earth to complete one revolution of its orbit, as measured against a fixed frame of reference (such as the fixed stars, Latin "sidera", singular "sidus"). Its average duration is days (365 d 6 h 9 min 9.76 s) (at the epoch J2000.0 = January 1, 2000, 12:00:00 TT).

Today the mean tropical year is defined as the period of time for the mean ecliptic longitude of the Sun to increase by 360 degrees. Since the Sun's ecliptic longitude is measured with respect to the equinox, the tropical year comprises a complete cycle of the seasons; because of the biological and socio-economic importance of the seasons, the tropical year is the basis of most calendars. The modern definition of mean tropical year differs from the actual time between passages of, e.g., the northward equinox for several reasons explained below. Because of the Earth's axial precession, this year is about 20 minutes shorter than the sidereal year. The mean tropical year is approximately 365 days, 5 hours, 48 minutes, 45 seconds, using the modern definition. (= days of 86400 SI seconds)

The anomalistic year is the time taken for the Earth to complete one revolution with respect to its apsides. The orbit of the Earth is elliptical; the extreme points, called apsides, are the perihelion, where the Earth is closest to the Sun (January 3 in 2011), and the aphelion, where the Earth is farthest from the Sun (July 4 in 2011). The anomalistic year is usually defined as the time between perihelion passages. Its average duration is days (365 d 6 h 13 min 52.6 s) (at the epoch J2011.0).

The draconic year, draconitic year, eclipse year, or ecliptic year is the time taken for the Sun (as seen from the Earth) to complete one revolution with respect to the same lunar node (a point where the Moon's orbit intersects the ecliptic). The year is associated with eclipses: these occur only when both the Sun and the Moon are near these nodes; so eclipses occur within about a month of every half eclipse year. Hence there are two eclipse seasons every eclipse year. The average duration of the eclipse year is

This term is sometimes erroneously used for the draconic or nodal period of lunar precession, that is the period of a complete revolution of the Moon's ascending node around the ecliptic: Julian years ( days; at the epoch J2000.0).

The full moon cycle is the time for the Sun (as seen from the Earth) to complete one revolution with respect to the perigee of the Moon's orbit. This period is associated with the apparent size of the full moon, and also with the varying duration of the synodic month. The duration of one full moon cycle is:

The lunar year comprises twelve full cycles of the phases of the Moon, as seen from Earth. It has a duration of approximately 354.37 days. Muslims use this for celebrating their Eids and for marking the start of the fasting month of Ramadan.
A Muslim calendar year is based on the lunar cycle.

The vague year, from "annus vagus" or wandering year, is an integral approximation to the year equaling 365 days, which wanders in relation to more exact years. Typically the vague year is divided into 12 schematic months of 30 days each plus 5 epagomenal days. The vague year was used in the calendars of Ancient Egypt, Iran, Armenia and in Mesoamerica among the Aztecs and Maya. It is still used by many Zoroastrian communities.

A heliacal year is the interval between the heliacal risings of a star. It differs from the sidereal year for stars away from the ecliptic due mainly to the precession of the equinoxes.

The Sothic year is the interval between heliacal risings of the star Sirius. It is currently less than the sidereal year and its duration is very close to the Julian year of 365.25 days.

The Gaussian year is the sidereal year for a planet of negligible mass (relative to the Sun) and unperturbed by other planets that is governed by the Gaussian gravitational constant. Such a planet would be slightly closer to the Sun than Earth's mean distance. Its length is:

The Besselian year is a tropical year that starts when the (fictitious) mean Sun reaches an ecliptic longitude of 280°. This is currently on or close to January 1. It is named after the 19th-century German astronomer and mathematician Friedrich Bessel. The following equation can be used to compute the current Besselian epoch (in years):

The TT subscript indicates that for this formula, the Julian date should use the Terrestrial Time scale, or its predecessor, ephemeris time.

The exact length of an astronomical year changes over time.

Mean year lengths in this section are calculated for 2000, and differences in year lengths, compared to 2000, are given for past and future years. In the tables a day is 86,400 SI seconds long.

An average Gregorian year is 365.2425 days (52.1775 weeks, hours, minutes or seconds). For this calendar, a common year is 365 days ( hours, minutes or seconds), and a leap year is 366 days ( hours, minutes or seconds). The 400-year cycle of the Gregorian calendar has days and hence exactly weeks.

The Great Year, or equinoctial cycle, corresponds to a complete revolution of the equinoxes around the ecliptic. Its length is about 25,700 years.

The Galactic year is the time it takes Earth's solar system to revolve once around the galactic center. It comprises roughly 230 million Earth years.

A seasonal year is the time between successive recurrences of a seasonal event such as the flooding of a river, the migration of a species of bird, the flowering of a species of plant, the first frost, or the first scheduled game of a certain sport. All of these events can have wide variations of more than a month from year to year.

In the International System of Quantities the symbol for the year as a unit of time is "a", taken from the Latin word "annus".

In English, the abbreviations "y" or "yr" are more commonly used in non-scientific literature, but also specifically in geology and paleontology, where "kyr, myr, byr" (thousands, millions, and billions of years, respectively) and similar abbreviations are used to denote intervals of time remote from the present.

NIST SP811 and ISO 80000-3:2006 support the symbol "a" as the unit of time for a year. In English, the abbreviations "y" and "yr" are also used.

The Unified Code for Units of Measure disambiguates the varying symbologies of ISO 1000, ISO 2955 and ANSI X3.50 by using:

where:

The International Union of Pure and Applied Chemistry (IUPAC) and the International Union of Geological Sciences have jointly recommended defining the annus, with symbol "a", as the length of the tropical year in the year 2000:

This differs from the above definition of 365.25 days by about 20 parts per million. The joint document says that definitions such as the Julian year "bear an inherent, pre-programmed obsolescence because of the variability of Earth’s orbital movement", but then proposes using the length of the tropical year as of 2000 AD (specified down to the millisecond), which suffers from the same problem. (The tropical year oscillates with time by more than a minute.)

The notation has proved controversial as it conflicts with an earlier convention among geoscientists to use "a" specifically for "years ago", and "y" or "yr" for a one-year time period.

For the following, there are alternative forms which elide the consecutive vowels, such as "kilannus", "megannus", etc. The exponents and exponential notations are typically used for calculating and in displaying calculations, and for conserving space, as in tables of data.

In astronomy, geology, and paleontology, the abbreviation "yr" for "years" and "ya" for years ago are sometimes used, combined with prefixes for thousand, million, or billion. They are not SI units, using "y" to abbreviate the English "year", but following ambiguous international recommendations, use either the standard English first letters as prefixes (t, m, and b) or metric prefixes (k, M, and G) or variations on metric prefixes (k, m, g). In archaeology, dealing with more recent periods, normally expressed dates, e.g. "22,000 years ago" may be used as a more accessible equivalent of a Before Present ("BP") date.

These abbreviations include:
Use of "mya" and "bya" is deprecated in modern geophysics, the recommended usage being "Ma" and "Ga" for dates Before Present, but "m.y." for the duration of epochs. This "ad hoc" distinction between "absolute" time and time intervals is somewhat controversial amongst members of the Geological Society of America.

Note that on graphs, using "ya" units on the horizontal axis time flows from right to left, which may seem counter-intuitive. If the "ya" units are on the vertical axis, time flows from top to bottom which is probably easier to understand than conventional notation.


How many officers are apart of The Metropolitan Police Department?

The Metropolitan Police, with a staff of more than 40,000 police officers, and over 2,800 civilian personnel, manages 102 stations in the prefecture.

Tokyo Metropolitan Police Department

The serves as the police force of Tokyo Metropolis. Founded in 1874, it is headed by a Superintendent-General, who is appointed by the National Public Safety Commission, and approved by the Prime Minister.

The main building of the Tokyo Metropolitan Police Department is located in the Kasumigaseki, Chiyoda ward, Tokyo. Built in 1980, it is 18 stories tall, a large wedge-shaped building with a cylindrical tower. It is easily seen from the street and a well-known landmark.

In 2007, the TMPD was under scrutiny when a serving TMPD officer was involved in an incident where he used his official sidearm to shoot a female person to death before he committed suicide.

The TMPD was investigating an incident in the Kamata Police Station in Ota Ward where a police officer committed suicide due to harassment at work. The chief in charge has been disciplined.

The Metropolitan Police Department is under the command of a Superintendent-General and reports directly to the Tokyo Metropolitan Public Safety Commission. The Superintendent-General can be appointed and replaced at any time as long as the prime minister and the TMPSC receives their approval.

Since the MPD is autonomous, it does not operate under the authority of any Regional Police Bureau.

The MPD commands the following bureaus:

The MPD also has its own academy, the Metropolitan Police Department Academy.

The ranks used in the TMPD have been slightly revised in 2013, changing only the English translation of some of the ranks used by the force.

Otherwise, these ranks are observed throughout its history.


Who won in the Battle of Ravenna?

The Battle of Ravenna in 729 was fought between the troops of the Eastern Roman (Byzantine) Exarchate of Ravenna and a force of Italians. This was in response to Emperor Leo III the Isaurian outlawing the veneration of holy icons, which Pope Gregory II was against. After a fierce battle, the Eastern Roman Army was overcome and thousands of Byzantines were killed.

Battle of Ravenna (729)

The Battle of Ravenna was fought between supporters of Orestes and supporters of Julius Nepos for control of the Western Roman Empire. In prelude to the battle, Orestes had been ordered to raise a large army to confront tribal rulers in Gaul. Instead he led his force against Emperor Julius Nepos in the capital Ravenna. Nepos was defeated and deposed, but managed to flee to Dalmatia. Orestes in turn enthroned his son Romulus Augustulus as Roman emperor. He was in turn overthrown by Odoacer in September 476 following the Roman defeat at Pavia.

Battle of Ravenna (475)

The Battle of Ravenna, fought on 11 April 1512, by forces of the Holy League, France and Ferrara was a major battle of the War of the League of Cambrai in the Italian Wars. Although the French and the Ferrarese drove the Spanish-Papal army from the field, their victory failed to help them secure northern Italy, and they would be forced to withdraw from the region entirely by August 1512.

Battle of Ravenna (1512)

Beginning in February 1512, the French forces in Italy, newly commanded by Gaston de Foix, Duc de Nemours, had been engaged in capturing cities in the Romagna and the Veneto, in an attempt to deny control of those regions to the forces of the Holy League. Although he had been successful in a number of sieges, Nemours was aware that the impending invasion of France by Henry VIII of England would cause much of his army to be withdrawn, and he was determined to force the main army of the Holy League into battle before that occurred. Thus, in late March, Nemours, together with an Italian contingent under Alfonso I d'Este, Duke of Ferrara, marched east from Bologna and laid siege to the city of Ravenna, which was defended by Papal troops.

Julius II, alarmed at the prospect of losing his last stronghold in the Romagna, demanded that an army be sent to relieve the city; Ramón de Cardona had to comply, and the Spanish army set out for Ravenna with a company of Papal troops in tow. By 9 April, they had passed Forlì, and were advancing north along the Ronco River towards the city, and on the next day had reached Molinaccio, only a mile south of the French positions, but still separated from them by the Ronco. Nemours, short on supplies and increasingly anxious to give battle before he was forced to withdraw from Italy, ordered a general attack for the following day.

The strengths, relative positions, and commanders of the component elements of both armies are unclear, and different arrangements are given by historians. The French army formed up in an arc to the east of Cardona's fortified camp; closest to the river were about 900 men-at-arms of the "vaward", under Jacques de La Palice and Alfonso d'Este. Next to this cavalry was the bulk of the infantry. According to Charles Oman, it consisted of three separate units: 3,500 Gascon crossbowmen, 5,000 landsknechts under Jacob Empser, and 3,000 Picards and Gascons under Thomas Bohier, the Seneschal of Normandy. Frederick Taylor groups the infantry into only two units: 9,500 landsknechts under Empser and 8,000 "Gascon archers and Picard pikemen" under the Seigneur de Molart. The men-at-arms of the "main-battle", consisting of 780 men, was commanded by either Bohier alone, or by Bohier together with the Vicomte de Lautrec, Louis d'Ars, and the Chevalier de Bayard. This cavalry occupied one of two positions: according to Oman and Thomas Arnold, it was placed in the arc to the left of the French infantry, while Taylor has it behind the cavalry of the "vaward", next to the river. Farther to the left of the French line—beyond the cavalry of the "main-battle", according to Arnold and Oman, or directly flanking the infantry, according to Taylor—was the "rearward" corps of the army, commanded by Yves d'Alégre. It consisted of about 4,000 mostly Italian infantry under Frederigo de Bozzolo, flanked, on the extreme left, by about 2,000 light cavalry under Gian Bernardo Caracciolo.

The arrangement of the Holy League army is similarly a matter of dispute; Oman comments that "the array of Cardona's army, though elaborately described by more than one narrator, is not very easy to make out." At the north end of the camp, near the river, was the cavalry of the "vaward", consisting of about 670 Papal men-at-arms under Fabrizio Colonna. Farther along the river were two more bodies of men-at-arms: the "main-battle", consisting of 565 men under the Marquis of La Palude, and the rearguard, consisting of 490 men under Alfonso Carvajal. Taylor divides the Holy League infantry into four blocks: three divisions of Spanish infantry, each consisting of four "colunellas" of 500–600 men each, and one formation of Papal infantry, numbering about 2,000, all under the general command of Pedro Navarro; Taylor places the formations of infantry in a deep column parallel to the river, on the far side of the cavalry, and perpendicular to the entrenchments. Oman and Arnold place the infantry in three lines running along the length of the entrenchements; no number is given for the first of these, but the second is given as consisting of 4,000 men, and the third, placed as a reserve, as including "three Spanish foot regiments" as well as the 2,000 Papal infantry. Beyond the infantry—to the far side of it from the river, according to Taylor, or at the end of its line, according to Oman and Arnold—was the light cavalry, consisting of 1,500–1,700 Spanish "ginetes" and Italian mounted arquebusiers under the command of Fernando d'Avalos, Marquis of Pescara. In his section on war wagons Arnold avers that the Spanish "had at least thirty carts mounting scythe blades, forward-projecting spears and organ guns.

The advancing French troops halted about two hundred paces from the enemy lines. The sporadic exchange of artillery fire that had been taking place since the French had begun to cross the Ronco now developed into a full-scale artillery duel between the two armies that lasted more than two hours. A new tactic, the open-field exchange of artillery fire was "the most violent cannonade between armies in the field that the world had yet seen", according to Taylor, and "the first of its kind in the historical record", according to Bert Hall.

De Foix placed the bulk of his artillery in front of the French right wing, directing its fire into the Holy League's camp. Navarro ordered his infantry to take cover—the troops hid in the trenches, or lay prone on the slopes of the river embankments—but Colonna's men-at-arms had no shelter available, and began to take heavy casualties from the cannon fire. The Spanish artillery, meanwhile, ignored the French cavalry and concentrated its fire on the massed Gascons and landsknechts in the French center. The Spanish fire was, according to Oman, "excessively murderous", and casualties among the French infantry were substantial; as many as 2,000 men were killed, and the Gascons were so shaken by the fire that the landsknechts were forced to push them back with pikes in order to keep them in line.

Not content with bombarding the camp from one side, the French moved to enfilade it from the flanks. The Duke of Ferarra, who had apparently been acting independently of the main army since the crossing of the Ronco, had moved twenty-four of his cannon around the rear of the French position, finally bringing them up on the left flank, facing Pescara's light cavalry. From this position, d'Este's guns inflicted heavy casualties on Pescara and Carvajal's cavalry; so intense was the fire that some of it overshot the camp, inflicting casualties on the French troops on the other side. Yves d'Alègre, meanwhile, had devised a similar plan on the other flank; re-crossing the Ronco with two heavy guns, he positioned them across the river from the Spanish camp—directly to the rear of Colonna's position. The fire of these two guns inflicted massive casualties on Colonna's closely packed cavalry.

Pressed from both sides by the fire of the French and Ferrarese artillery, the Holy League's cavalry could not hold their positions indefinitely. The first to move were the heavy cavalry of the rearguard under Carvajal, riding out from the entrenchments towards the Ferrarese guns on the French left; according to Taylor, Carvajal's advance was disorderly and possibly spontaneous. Carvajal was quickly joined by Pescara's light cavalry and by the Marquis of La Palude, both having been sent forward by Cardona; together, these bodies of cavalry advanced on the French line, Palude moving directly forwards while Pescara attempted a flanking movement. The target of the cavalry attack is inconsistently named among contemporary sources; both Oman and Taylor agree that it must have been the heavy cavalry of the French "main-battle", commanded by Foix, Lautrec, and the Seneschal of Normandy, which had apparently moved towards the French left.

Carvajal, Pescara, and Palude converged on the French cavalry, which split into two bodies and met both Spanish attacks head-on. The initial Spanish charges were unsuccessful in breaking the French line; Taylor attributes their failure to the depleted morale of the Spanish cavalry after the artillery bombardment, the effect of "ditches and vegetation" on the Spanish formations, the better tactics of the French, and the arrival of reinforcements sent by La Palice from the French vanguard. The bodies of French and Spanish cavalry then engaged in a lengthy fight along the left of the French positions.

Meanwhile, Fabrizio Colonna, having seen the other Spanish cavalry engaged, rode out between the Ronco and the Spanish trenches and charged the French line; his target is similarly the subject of disagreement among contemporary sources, but Oman and Taylor agree that he must have attacked the portion of the French vanguard under La Palice which the latter had not sent to assist Foix in the center. As Colonna and La Palice fought along the French right, d'Alègre, who had earlier been summoned by La Palice, arrived with 400 fresh heavy cavalry, as well as the infantry of the French reserve. Colonna's formation, pressed from multiple directions, began to disintegrate, with some of his men-at-arms fleeing the field and others retreating south to where the other Spanish cavalry was engaged.

D'Alègre followed the retreating Spanish troops to the center, where the remnants of the Spanish cavalry were engaged in a desperate melee against the French. Finally, when a part of the French vanguard joined the fight as well, the Spanish cavalry broke; Pescara and La Palude were taken prisoner, Colonna retreated back into the Spanish entrenchments, and Carvajal and Cardona fled south-west towards Cesena. A large part of the French cavalry pursued the retreating Spanish, while the others turned to take part in the infantry fight which had unfolded in the meantime.

As the Spanish cavalry was making its initial attack, Foix had sent orders for the French infantry to advance on the Holy League's camp. A mixed group of 2,000 Gascon crossbowmen and 1,000 Picard pikemen, gathered from Molart's and Bozollo's troops, advanced towards the camp; according to Taylor, they moved along a path between the embankment and the river, and were shielded from view by the former. The Gascons advanced to the edge of the Spanish entrenchments and began to fire onto the Spanish infantry; according to Oman, they were immediately driven back by "a blistering fire of arquebuses and swivel guns", while Taylor writes that Navarro moved the Papal infantry forward to engage them.

The main column of landsknechts had meanwhile made its way to the edge of the Spanish entrenchments, and begun to force its way into the fortified camp. Jacob Empser and his lieutenant Fabian von Schlabendorf were both killed in the initial push, but parts of the German column finally crossed the ditch and engaged the waiting Spanish infantry hand-to-hand. The Spanish swordsmen inflicted massive casualties among the landsknechts—who were unable to defend themselves with long pikes at such close quarters—and the German column recoiled back across the trenches, having suffered more than a thousand casualties.

The landsknechts and the Gascons proceeded to attack once more, with even greater casualties. Fabrizio Colonna, who had by this time returned to the camp with the remnants of his cavalry, charged into the flank of the attacking infantry; he would write that "with 200 lances he could have retrieved the fortune of the day". Two companies of Spanish infantry attacked the Gascons engaged on the riverbank, breaking their formation, killing Molart, and pursuing them back towards the French artillery positions. The remaining infantry on both sides continued meanwhile to struggle across the entrenchments.

At this juncture, the French cavalry—both those that had returned from the pursuit of Cardona and those that had remained on the field—descended on the Spanish infantry from all sides. Together with the German and Gascon infantry, which had reformed and now renewed its attacks, the French cavalry overwhelmed the Spanish formations, inflicting terrible casualties; Colonna and Navarro were both wounded and captured as they tried to rally the defenders. A few thousand of the Spanish infantry managed to escape, fleeing towards Cesena and Forlì; the others were "ridden over and trampled down", according to Oman.

The two Spanish companies which had earlier routed the Gascons, having found their path north barred by the French rearguard under the Bastard du Fay, had meanwhile retraced their path along the river back towards the camp. Marching south along the embankment, they were attacked by Gaston de Foix and his personal staff, numbering about fifteen; in the ensuing melee, the French knights were scattered, Foix was killed, and the Spanish proceeded to withdraw from the field. A few miles from the battlefield, the Spanish infantry encountered Bayard, returning from his pursuit of Cardona; lacking the numbers to break them, Bayard let them pass, not knowing that they had just killed his commander.

The death of Gaston de Foix was a huge blow to the French, and his men were very sad to hear of his death. The young, talented general had a very high command level and had masterminded a remarkable string of victories in Italy. He was inspiring and faithful to his men. The Italian Wars might have taken a very different course had he survived the battle.

Following the death of Gaston de Foix, command of the French army fell to La Palice, who had little interest in pursuing the retreating Spanish forces, preferring instead to return to the siege of Ravenna. The city soon fell, and the French proceeded to thoroughly sack it. However, much of the French army was withdrawn to France following the battle, and La Palice was forced to extricate himself from Italy in August by renewed efforts on the part of the Holy League.

The Spanish forces in Italy were almost entirely destroyed at Ravenna, but Cardona would raise another army and appear in Lombardy in 1513. In the meantime, both Navarro and Colonna would see combat, Colonna in command of an Italian army and Navarro in the service of Francis I of France.

A month before the battle, multiple sources reported a monstrous birth which became known as the Monster of Ravenna. This child's terrying features included a horn on its forehead, wings, an eye on its knee, and a clawed foot, according to Florentine chronicler Luca Landucci. Its appearance was evidently a cause for alarm, and news spread across Europe in the diaries of contemporary writers.

Most accounts, including that of Landucci's, associate the "monster's" appearance with the battle it preceded; its appearance was taken for a bad omen of future suffering, and the French medical professional Ambroise Paré opined that the creature's birth was a direct sign of God's wrath, brought to bear in the form of Louis XII's army. Regardless, the Monster of Ravenna acquired theological implications which evolved beyond the one battle and persisted well into the Protestant Reformation.