1255

Millennium:	2nd millennium
Centuries:	12th century 13th century 14th century
Decades:	1230s 1240s 1250s 1260s 1270s
Years:	1252 1253 1254 1255 1256 1257 1258

1255 in various calendars

Gregorian calendar	1255 MCCLV
Ab urbe condita	2008
Armenian calendar	704 ԹՎ ՉԴ
Assyrian calendar	6005
Balinese saka calendar	1176–1177
Bengali calendar	662
Berber calendar	2205
English Regnal year	39 Hen. 3 – 40 Hen. 3
Buddhist calendar	1799
Burmese calendar	617
Byzantine calendar	6763–6764
Chinese calendar	甲寅年 (Wood Tiger) 3952 or 3745     — to — 乙卯年 (Wood Rabbit) 3953 or 3746
Coptic calendar	971–972
Discordian calendar	2421
Ethiopian calendar	1247–1248
Hebrew calendar	5015–5016
Hindu calendars
- Vikram Samvat	1311–1312
- Shaka Samvat	1176–1177
- Kali Yuga	4355–4356
Holocene calendar	11255
Igbo calendar	255–256
Iranian calendar	633–634
Islamic calendar	652–653
Japanese calendar	Kenchō 7 (建長７年)
Javanese calendar	1164–1165
Julian calendar	1255 MCCLV
Korean calendar	3588
Minguo calendar	657 before ROC 民前657年
Nanakshahi calendar	−213
Thai solar calendar	1797–1798
Tibetan calendar	阳木虎年 (male Wood-Tiger) 1381 or 1000 or 228     — to — 阴木兔年 (female Wood-Rabbit) 1382 or 1001 or 229

Year 1255 (MCCLV) was a common year starting on Friday (link will display the full calendar) of the Julian calendar.

Events

By place

Asia

• Hulagu Khan begins his campaign to destroy the remaining Muslim states in southwestern Asia, with the main targets being the Nizari Ismaili strongholds and the Abbasid Caliphate in Baghdad.

Europe

• 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.
• August – The final Cathar stronghold in southern France falls, eliminating their last refuge, since the Roman Catholic Church began the Albigensian Crusade to crush the sect in 1209.
• The death of Little Saint Hugh of Lincoln prompts the persecution of Jews in England, based on the blood libel.
• Lisbon becomes the capital of Portugal.
• A survey of royal privileges is conducted, which is included in the Hundred Rolls, an English census seen as a followup to the Domesday Book completed in 1086; the Hundred Rolls is later completed with two larger surveys, in 1274/1275 and 1279/1280.
• Königsberg (now Kaliningrad) is founded by the Teutonic Knights in Prussia, and named in honour of King Ottokar II of Bohemia.
• Theodore II Laskaris, 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 lands of the House of Nassau are divided, not to be reunited until 1806.
• King Béla IV of Hungary grants Banská Bystrica the municipal rights of a royal town.

By topic

Arts and culture

• The Gothic cathedral at Bourges, France, is completed (it is now a UNESCO World Heritage Site).

Markets

• At the death of Bernardo Bonsignori, his brother, Orlando, is left sole director of the largest banking firm in western Europe, the Gran Tavola of Siena.

Births

• July – Albert I of Germany, Holy Roman Emperor (d. 1308)
• October 23 – Ferdinand de la Cerda, Spanish noble (d. 1275)
• William de Ros, 1st Baron de Ros, claimant to the crown of Scotland (d. 1317)
• Duccio di Buoninsegna, Sienese painter (d. 1319)
• Margherita Colonna, Italian abbess (d. 1284)
• Grand Prince Andrey of Gorodets (approximate date; d. 1304)
• Adolf of Nassau-Weilburg, King of the Romans (approximate date; d. 1298)

Deaths

• May 1 – Walter de Gray, English prelate and statesman
• August 27 – Little Saint Hugh of Lincoln (b. 1247)
• Batu Khan, Mongol ruler and founder of the Blue Horde
• Alice, Countess of Bigorre, ruler
• Jarler, Archbishop of Uppsala since 1236
• Sundiata Keita, semi-historical hero and founder of the Mali Empire (approximate date; b. c. 1190)
• December 1 or 2 – Muhammad III of Alamut, the Nizari Ismaili Imam