|Ab urbe condita||1891|
|Balinese saka calendar||1059–1060|
|English Regnal year||3 Ste. 1 – 4 Ste. 1|
|Chinese calendar||丁巳年 (Fire Snake)|
3834 or 3774
— to —
戊午年 (Earth Horse)
3835 or 3775
|- Vikram Samvat||1194–1195|
|- Shaka Samvat||1059–1060|
|- Kali Yuga||4238–4239|
|Japanese calendar||Hōen 4|
|Minguo calendar||774 before ROC|
|Seleucid era||1449/1450 AG|
|Thai solar calendar||1680–1681|
1264 or 883 or 111
— to —
1265 or 884 or 112
|Wikimedia Commons has media related to 1138.|
- March 13
- April 10 – Robert Warelwast is nominated as Bishop of Exeter.
- July – Bavaria is taken away from the Welfen Henry X, Duke of Bavaria, and given to the Margrave Leopold IV of Austria.
- August 22 – Battle of the Standard in Yorkshire: David I of Scotland is defeated by the English.
- October 11 – An earthquake in Aleppo, Syria, kills about 230,000 people.
- November 5 – Lý Anh Tông is enthroned as emperor of Đại Việt at the age of two, starting a 37-year reign.
- The earldom of Pembroke, created for Gilbert de Clare, is the first earldom created by the Norman kings within the borders of Wales.
- The consuls of Florence are first mentioned, indicating that the city has become an independent and self-governing commune.