|Ab urbe condita||1955|
|Balinese saka calendar||1123–1124|
|English Regnal year||3 Joh. 1 – 4 Joh. 1|
|Chinese calendar||辛酉年 (Metal Rooster)|
3898 or 3838
— to —
壬戌年 (Water Dog)
3899 or 3839
|- Vikram Samvat||1258–1259|
|- Shaka Samvat||1123–1124|
|- Kali Yuga||4302–4303|
|Japanese calendar||Kennin 2|
|Minguo calendar||710 before ROC|
|Thai solar calendar||1744–1745|
1328 or 947 or 175
— to —
1329 or 948 or 176
|Wikimedia Commons has media related to 1202.|
- May – October – The Fourth Crusade gathers in Venice.
- July – John, King of England rescues his mother, Eleanor of Aquitaine, from near capture by the rebellious forces of Arthur I, Duke of Brittany.
- July 27 – Battle of Basian: Georgians defeat the Seljuqids of Rüm.
- August 1 – Arthur I, Duke of Brittany is captured in Mirebeau, north of Poitiers, during a battle with John, King of England.
- November 10–23 – Fourth Crusade – Siege of Zara: In the first major action of the Crusade, the Crusaders besiege and conquer Zadar in Dalmatia. Unable to pay the Republic of Venice in cash for its contributions to the Crusade, the Crusaders agree to sack the city (an economic rival to Venice), despite letters from Pope Innocent III forbidding such an action, and threatening excommunication (which is carried out at the urging of Emeric, King of Hungary). This is the first attack against a Catholic city by Catholic Crusaders.
- The Almohad fleet expels the Banu Ghaniya from the Balearic Islands.
- The Livonian Brothers of the Sword is founded, to support a crusade against the inhabitants of Medieval Livonia.
- Pope Innocent III reasserts his right to evaluate and crown the Holy Roman Emperor, in a letter to Berthold V, Duke of Zähringen.
- Danes make a crusade to Finland which is led by the Archbishop of Lund Anders Sunesen and his Brother.
- Leonardo Fibonacci of Pisa writes Liber Abaci, about the modus Indorum, the Hindu–Arabic numeral system, including the use of zero; it is the first major work in Europe to move away from the use of Roman numerals.
- Approximate date – The first jesters are hired in European courts.
- June 2 – Margaret II, Countess of Flanders (d. 1278)
- Matilda II, Countess of Boulogne, spouse of King Afonso III of Portugal (d. 1262)
- Qin Jiushao, Chinese mathematician of the Song dynasty (d. 1261)
- January 9 – Birger Brosa, Swedish Jarl
- March 9 – Sverre Sigurdsson, King of Norway since 1184
- March 13 – Mieszko III the Old, king of Poland (b. c. 1121)
- May 7 – Hamelin de Warenne, Earl of Surrey
- November 12 – Canute VI of Denmark (b. 1163)
- Cathal Carragh Ua Conchobair, King of Connacht
- Alain de Lille, French theologian and poet (b. c. 1128)
Science and Technology
- 1202 was a program alarm during the lunar descent phase of the Apollo 11 Lunar Module caused by a data overflow in the Apollo Guidance Computer (AGC)
- Warren, W. L. (1961). King John. University of California Press. pp. 77–78.
- Picard, Christophe (1997). La mer et les musulmans d'Occident VIIIe-XIIIe siècle. Paris: Presses Universitaires de France.
- Georg Haggren; Petri Halinen; Mika Lavento; Sami Raninen ja Anna Wessman (2015). Muinaisuutemme jäljet. Helsinki: Gaudeamus. p. 380.