* 1204 – The Crusaders of the Fourth Crusade breach the walls of Constantinople and enter the city, which they completely occupy the following day.

* 1204 – Eleanor of Aquitaine ( b. 1122 )

* 1204 – Constantinople falls to the Crusaders of the Fourth Crusade, temporarily ending the Byzantine Empire.

* Michael Angold ( 1997 ), The Byzantine Empire, 1025 – 1204, Longman, 2nd ed., pp. 136 – 70.

* Michael Angold, The Byzantine Empire, 1025 – 1204: A Political History, second edition ( London and New York, 1997 )

Alexios V Doukas, surnamed Mourtzouphlos (, d. December 1205, Constantinople ) was Byzantine Emperor ( 5 February – 12 April 1204 ) during the second and final siege of Constantinople by the participants of the Fourth Crusade.

* Anna Maria of Hungary ( c. 1204 – 1237 ), wife of Tzar Ivan Asen II of Bulgaria

The Byzantine Empire, 1025 – 1204.

* 1263 – King Haakon IV of Norway ( b. 1204 )

* 1204 – Abû ' Uthmân Sa ' îd ibn Hakam al Qurashi, ruler of Minorca ( d. 1282 )

* 1204 – Maimonides, Spanish rabbi and philosopher ( b. 1135 )

Eleanor of Aquitaine () ( 1122 or 1124 – 1 April 1204 ) was one of the wealthiest and most powerful women in Western Europe during the High Middle Ages.

* 1192 – 1200 / 1204: Frederick I ( also count of Zollern as Frederick III )

* The Mishneh Torah ( also known as the Yad HaHazaka for its 14 volumes ; " yad " has a numeric value of 14 ), by Maimonides ( Rambam ; 1135 – 1204 ).

* 1204 – King Philip Augustus of France conquers Rouen.

Maimonides ( 1135 – 1204 CE ) relates that until the Babylonian exile ( 586 BCE ), all Jews composed their own prayers, but thereafter the sages of the Great Assembly composed the main portions of the siddur.

Byzantine empresses: women and power in Byzantium, AD 527 – 1204.

* 1204 – Baldwin IX, Count of Flanders is crowned as the first Emperor of the Latin Empire.

The Charte aux Normands granted by Louis X of France in 1315 ( and later re-confirmed in 1339 ) – like the analogous Magna Carta granted in England in the aftermath of 1204 – guaranteed the liberties and privileges of the province of Normandy.

* 1182 – Minamoto no Yoriie, Japanese shogun ( d. 1204 )

* " Historical Dynamics in a Time of Crisis: Late Byzantium, 1204 – 1453 " ( discussion of social dynamics from the point of view of historical studies )

* Heinrich of Klingen ( 1200 – 1204 )

* Frederick IV ( 1204 – 1251 / 1255 ), also Burgrave of Nuremberg ( as Frederick II ) until 1218

Simon IV de Montfort, Seigneur de Montfort-l ' Amaury, 5th Earl of Leicester ( 1160 – 25 June 1218 ), also known as Simon de Montfort the elder, was a French nobleman who took part in the Fourth Crusade ( 1202 – 1204 ) and was a prominent leader of the Albigensian Crusade.

By the beginning of 1204, Isaac II and Alexios IV had inspired little confidence among the people of Constantinople in their efforts to defend the city from the Latins and Venetians, who were restless and rioted when the money and aid promised by Alexios IV was not forthcoming.

Although besieged on numerous occasions by various peoples, it was taken only in 1204 by the army of the Fourth Crusade, in 1261 by Michael VIII, and in 1453 by the Ottoman Sultan Mehmed II.

Philip II of France | Phillip II's successful invasion of Duchy of Normandy | Normandy in 1204 ; blue arrows indicate the movement of Philip II's forces and light blue Philip's Breton allies

In 1204, during the reign of England's King John, mainland Normandy was taken from England by France under Philip II of France.

The silver altarpiece of patriarch Pellegrinus II ( 1195 − 1204 ) in the cathedral of Cividale was printed with individual letter punches.

* William II Longespee ( c. 1204 – 1250 )

Alarmed by the Georgian successes, Süleymanshah II, the resurgent Seljuqid sultan of Rûm, rallied his vassal emirs and marched against Georgia, but his camp was attacked and destroyed by David Soslan at the battle of Basian in 1203 or 1204.

* 1204 BC: Theseus, legendary King of Athens, is deposed after a reign of 30 years and succeeded by Menestheus, great-grandson of Erichthonius II of Athens and second cousin of Theseus ' father Aegeus.

* 1204 BC: Theseus, legendary King of Athens, is deposed after a reign of 30 years and succeeded by Menestheus, great-grandson of Erichthonius II of Athens and second cousin of Theseus ' father Aegeus.

* Agnes ( 1171 – after 1204 ), who was betrothed to Alexius II Comnenus ( 1180 – 1183 ) but married ( 1 ) Andronicus I Comnenus ( 1183 – 1185 ); ( 2 ) Theodore Branas ( 1204 )

On 24 June 1204, Philip II Augustus of France entered Rouen and annexed Normandy to the French Kingdom.

In 1204, the city was bought by the Republic of Venice as part of a complicated political deal which involved among other things, the Crusaders of the Fourth Crusade restoring the deposed Eastern Roman Emperor Isaac II Angelus to his throne.

After the Fourth Crusade in 1204, a Byzantine successor state was founded there with support of Queen Tamar of Georgia, the Empire of Trebizond, which ruled part of the Black Sea coast from Trebizond until 1461, when its ruler, David, surrendered to Mehmed II, ruler of the Ottoman Empire.

He and the king had a falling out in the aftermath of the loss of the duchy, when he was sent with the earl of Leicester as ambassadors to negotiate a truce with King Philip II of France in 1204.

The city became a possession of the Kings of Aragon in 1204 by the marriage of Peter II of Aragon with Marie of Montpellier, who brought the city as her dowry.

Isaac II Angelos ( or Angelus ) ( Greek: Ισαάκιος Β ’ Άγγελος, Isaakios II Angelos ) ( September 1156 – January 1204 ) was Byzantine Emperor from 1185 to 1195, and again from 1203 to 1204.

At the end of January, 1204, the influential court official Alexios Doukas Mourtzouphlos took advantage of riots in the capital to imprison Alexios IV and seize the throne as Emperor Alexios V. At this point Isaac II died, allegedly of shock, while Alexios IV was strangled on 28 or 29 January.

The castle was captured by King Philip II of France in 1204.