|This article needs additional citations for verification. (February 2015)|
|Centuries:||12th century – 13th century – 14th century|
|Decades:||1190s 1200s 1210s – 1220s – 1230s 1240s 1250s|
|Years:||1218 1219 1220 – 1221 – 1222 1223 1224|
|1221 by topic|
|State leaders – Sovereign states|
|Birth and death categories|
|Births – Deaths|
|Establishments and disestablishments categories|
|Establishments – Disestablishments|
|Art and literature|
|1221 in poetry|
|Ab urbe condita||1974|
|English Regnal year||5 Hen. 3 – 6 Hen. 3|
|Chinese calendar||庚辰年 (Metal Dragon)
3917 or 3857
— to —
辛巳年 (Metal Snake)
3918 or 3858
|- Vikram Samvat||1277–1278|
|- Shaka Samvat||1143–1144|
|- Kali Yuga||4322–4323|
|Japanese calendar||Jōkyū 3
|Minguo calendar||691 before ROC
|Thai solar calendar||1763–1764|
|Wikimedia Commons has media related to 1221.|
- January – The Mongol army under Jochi captures the city of Gurganj (modern-day Konye-Urgench in Turkmenistan) and massacres the inhabitants, reported by contemporary scholars as being over a million.
- February – The oasis city of Merv on the Silk Road is sacked by the Mongols under Tolui at the orders of Genghis Khan. Contemporary scholars report over a million people are systematically killed in a genocide.
- May 13 – Emperor Juntoku is forced to abdicate and is briefly succeeded by his 2-year-old son Emperor Chūkyō on the throne of Japan. Ex-Emperor Go-Toba leads the unsuccessful Jōkyū War against the Kamakura shogunate.
- June 16 – The Jews of Erfurt, Germany were massacred al Kiddush Hashem. This day was observed as a fast day for many years.
The Jews were falsely accused of a ritual murder. A crowd stormed the synagogue where the Jews had gathered. As usual the threat was baptism or death. The Jewish quarter including the synagogue was razed, many Jews were tortured and killed. Among the martyrs were Shem Tov ha-Levi and Rabbi and Mrs. Shmuel Kalonymos, Hy"d.
- July 29 – 10-year-old Emperor Go-Horikawa ascends to the Chrysanthemum Throne of Japan.
- Mid-December – John III Doukas Vatatzes becomes Byzantine Emperor (in the Empire of Nicaea).
- A large and highly efficient Mongol army, dispatched under Subutai by Genghis Khan to Georgia, defeats two Georgian armies around Tbilisi, but lacks the will or equipment to besiege the city.
- Genghis Khan enters the Indus Valley in modern-day Pakistan.
- Majd al-Mulk al-Muzaffar, the grand vizier of Greater Khorasan, is killed in a genocide by the Mongol invaders.
- The Maya of the Yucatán revolt against the rulers of Chichen Itza.
- Sultan al-Kamil, son of al-Adil ("Saphadin") who was a brother of Saladin, offers Jerusalem to the Crusaders for ten years in return for Damietta, which the Crusaders eventually give up in exchange for a safe retreat from the Nile Delta.
- The city of Nizhny Novgorod in Russia is founded.
- October 9 – Salimbene di Adam, Italian chronicler
- November 23 – King Alfonso X of Castile (d. 1284)
- Bonaventure, Italian theologian and saint (d. 1274)
- Boleslaus the Pious, Duke of Greater Poland (d. 1279)
- August 6 – Saint Dominic, Spanish founder of the Dominicans (b. 1170)
- October 4 – William III Talvas, Count of Ponthieu (b. 1179)
- October 21 – Alix of Thouars, Duchess of Brittany (b. 1201)
- Roger Bigod, 2nd Earl of Norfolk
- Mutukan, 1st Son of Chagatai Khan
- Perkins, George W. "Mourning Attire". The Clear Mirror: A Chronicle of the Japanese Court During the Kamakura Period (1185-1333). Stanford University Press. p. 59. ISBN 0804763887.
- George Akropolites. The History. Trans. Ruth Macrides. New York: Oxford University Press, 2007, p. 160.
- Jeune, Sir Francis Henry (1867). The Mahometan Power in India: The Arnold Prize Essay for 1867. p. 20.
- Lindsay Brown; Paul Clammer; Rodney Cocks (2008). "North-west Frontier Province". Pakistan and the Karakoram Highway. Lonely Planet. p. 189. ISBN 1741045428.
- Richard Bodley Scott; Graham Briggs; Rudy Scott Nelson (2009). Blood and Gold: The Americas at War. Osprey Publishing. p. 35. ISBN 1846036917.
- Bancroft, Hubert Howe (1883). The native races. 1882-86. British Columbia: History Company.
- Rayborn, Tim (9 October 2014). "Popular Religion, Heresy and Mendicancy". Against the Friars: Antifraternalism in Medieval France and England. McFarland. p. 17. ISBN 0786468319.
- Francisco Márquez Villanueva; Carlos Alberto Vega (1990). Alfonso X of Castile, the learned king, 1221-1284: an international symposium, Harvard University, 17 November 1984. Dept. of Romance Languages and Literatures of Harvard University. p. 165. ISBN 0940940434.
- M. Walsh, ed. (1991). Butler's Lives of the Saints. New York: HarperCollins. p. 216.
- Perkins, Charles Callahan (1864). "The Arca Di S. Domenico.". Tuscan sculptors: their lives, works and times, Volume 1. Longman, Green, Longman, Roberts, & Green. p. 19.