|1245 by topic|
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|Births – Deaths|
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|Establishments – Disestablishments|
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- February 21 – Thomas (bishop of Finland) is granted resignation by Pope Innocent IV, after having confessed to torture and forgery.
- April 16 – Pope Innocent IV sends Giovanni da Pian del Carpine to the Mongol court, suggesting (amongst other things) that the Mongols convert to Christianity, and join the Crusades.
- June 28 – The First Council of Lyon opens, in the course of which Frederick II, Holy Roman Emperor, is excommunicated and deposed, and the Seventh Crusade is proclaimed.
- August 1 – The second of two papal bulls refers to the marriage of King Sancho II of Portugal to Mécia Lopes de Haro, and decrees the deposition of the king.
- date unknown
- January 16 – Edmund Crouchback, 1st Earl of Lancaster, son of Henry III of England (d. 1296)
- April 3 – King Philip III of France (d. 1285)
- November 14 — Sang Sapurba, first Malay King and progenitor of Malay kings in Malacca and Majapahit kingdoms (d. 1316)
- date unknown – Boniface of Savoy
- August 19 – Ramon Berenguer IV, Count of Provence (b. 1195)
- August 21 – Alexander of Hales, English theologian
- Rusudan of Georgia, queen regnant of Georgia (b. 1194)