|Ab urbe condita||1971|
|Balinese saka calendar||1139–1140|
|English Regnal year||2 Hen. 3 – 3 Hen. 3|
|Chinese calendar||丁丑年 (Fire Ox)|
3914 or 3854
— to —
戊寅年 (Earth Tiger)
3915 or 3855
|- Vikram Samvat||1274–1275|
|- Shaka Samvat||1139–1140|
|- Kali Yuga||4318–4319|
|Japanese calendar||Kenpō 6|
|Minguo calendar||694 before ROC|
|Thai solar calendar||1760–1761|
1344 or 963 or 191
— to —
1345 or 964 or 192
|Wikimedia Commons has media related to 1218.|
- May 24 – The Fifth Crusade leaves Acre for Egypt.
- May 30 – Damietta is besieged by the knights of the Fifth Crusade.
- Minamoto no Sanetomo becomes Udaijin of Japan.
- The Kara-Khitan Khanate is destroyed by Genghis Khan's Mongolian cavalry.
- Genghis Khan's Mongols, under the leadership of his eldest son Jochi, conduct a second campaign against the Kyrgyz.
- Genghis Khan proposes to the Khwarazm shah of Persia that he accept Mongol overlordship, and establish trade relations.
- March – The Treaty of Worcester recognises Llywelyn the Great as regent of south Wales.
- July – Spain: In order to facilitate the movement of Reconquista, Pope Honorius III reverses Innocent III’s earlier judgement, and declares Ferdinand III of Castile legitimate heir to the Kingdom of Leon.
- The northern French city of Rheims emits the first recorded public life annuity in medieval Europe. Theretofore, this type of instrument had been mostly issued by religious institutions. The emission by Rheims is the first evidence of a consolidation of public debt that is to become common in the Langue d'Oïl, the Low Countries and Germany.
- February 12 – Kujō Yoritsune, Japanese shōgun (d. 1256)
- May 1
- October 30 – Emperor Chūkyō of Japan (d. 1234)
- date unknown
- January 10 – Hugh I of Cyprus
- February 2 – Konstantin of Rostov, Prince of Novgorod (b. 1186)
- February 18 – Berthold V, Duke of Zähringen (b. 1160)
- May 19 – Otto IV, Holy Roman Emperor
- June 25 – Simon de Montfort, 5th Earl of Leicester, French crusader (b. 1160)
- July 6 – Odo III, Duke of Burgundy (b. 1166)
- November 12 – Henry de Abergavenny, Prior of Abergavenny and Bishop of Llandaff
- December 28 – Robert II, Count of Dreux (b. 1154)
- "BBC Wales History". Archived from the original on November 25, 2007. Retrieved 2007-12-10.
- Linehan, Peter (1999). "Chapter 21: Castile, Portugal and Navarre". In David Abulafia (ed.). The New Cambridge Medieval History c.1198-c.1300. Cambridge: Cambridge University Press. pp. 668–671. ISBN 0-521-36289-X.
- Zuijderduijn, Jaco (2009). Medieval Capital Markets. Markets for renten, state formation and private investment in Holland (1300-1550). Leiden; Boston: Brill. ISBN 978-9-00417565-5.