1258
| Years: 1255 1256 1257 - 1258 - 1259 1260 1261 | |
| Decades: 1220s 1230s 1240s - 1250s - 1260s 1270s 1280s | |
| Centuries: 12th century - 13th century - 14th century | |
Events
- February 10 - Mongols overrun Baghdad, burning it to the ground and killing 800,000 citizens
- Llywelyn the Last declares himself Prince of Wales. He is the final ruler of an independent Wales, before its conquest by the English.
- John IV Lascaris succeeds his father Theodore II Lascaris as emperor of Nicaea. Due to his young age, he is appointed as regent Michael VIII Palaeologus.
- Osman I, founder of the Ottoman Empire
- Theodore II Lascaris, emperor of Nicaea