|Centuries:||12th century – 13th century – 14th century|
|Decades:||1220s 1230s 1240s – 1250s – 1260s 1270s 1280s|
|Years:||1252 1253 1254 – 1255 – 1256 1257 1258|
- August – The final Cathar stronghold in southern France falls, eliminating the last refuge of the heretical Cathars after the Roman Catholic Church engaged in a program to crush the sect, starting in 1209 with the Albigensian Crusade.
- The death of Little Saint Hugh of Lincoln prompts persecution of Jews in England on accusations of blood libel.
- Lisbon becomes the capital of the Kingdom of Portugal.
- The Gothic cathedral at Bourges, France, is completed. It is now a UNESCO World Heritage Site.
- A survey of royal privileges is conducted, which is included in the Hundred Rolls, an English census seen as a follow up to the Domesday Book completed in 1086; the Hundred Rolls is later completed with two larger surveys in 1274/1275 and 1279/1280.
Central and Eastern EuropeEdit
- May – William of Rubruck from Constantinople returns to Cyprus from his missionary journey to convert the Tatars of central and eastern Asia, his efforts having been unsuccessful.
- Königsberg (now Kaliningrad) is founded in Prussia.
- Theodore II Lascaris, Byzantine Emperor (in exile in the Empire of Nicaea), conducts a military campaign to recover Thrace from the Bulgarians. He concludes the task successfully a year later in 1256.
- The Duchy of Bavaria is split into Upper and Lower Bavaria
- The German state of Nassau is divided, not to be reunited until 1806.
- King Béla IV of Hungary grants Banská Bystrica municipal rights of a royal town.
- Albert I of Germany, Holy Roman Emperor (died 1308)
- William de Ros, 2nd Baron de Ros, claimant to the crown of Scotland (died 1317)
- Duccio di Buoninsegna, Sienese painter (died 1319)
- Grand Prince Andrey of Gorodets (approximate date; died 1304)
- Adolf of Nassau-Weilburg, King of the Romans (approximate date; died 1298)