1231

1231 (MCCXXXI) was a common year starting on Wednesday of the Julian calendar, the 1231st year of the Common Era (CE) and Anno Domini (AD) designations, the 231st year of the 2nd millennium, the 31st year of the 13th century, and the 2nd year of the 1230s decade. As of the start of 1231, the Gregorian calendar was 7 days ahead of the Julian calendar, which was the dominant calendar of the time.

1231 in other calendars

Gregorian calendar	1231 MCCXXXI
Ab urbe condita	1984
Armenian calendar	680 ԹՎ ՈՁ
Assyrian calendar	5981
Balinese saka calendar	1152–1153
Bengali calendar	638
Berber calendar	2181
English Regnal year	15 Hen. 3 – 16 Hen. 3
Buddhist calendar	1775
Burmese calendar	593
Byzantine calendar	6739–6740
Chinese calendar	庚寅年 (Metal Tiger) 3927 or 3867     — to — 辛卯年 (Metal Rabbit) 3928 or 3868
Coptic calendar	947–948
Discordian calendar	2397
Ethiopian calendar	1223–1224
Hebrew calendar	4991–4992
Hindu calendars
- Vikram Samvat	1287–1288
- Shaka Samvat	1152–1153
- Kali Yuga	4331–4332
Holocene calendar	11231
Igbo calendar	231–232
Iranian calendar	609–610
Islamic calendar	628–629
Japanese calendar	Kangi 3 (寛喜３年)
Javanese calendar	1140–1141
Julian calendar	1231 MCCXXXI
Korean calendar	3564
Minguo calendar	681 before ROC 民前681年
Nanakshahi calendar	−237
Thai solar calendar	1773–1774
Tibetan calendar	ལྕགས་ཕོ་སྟག་ལོ་ (male Iron-Tiger) 1357 or 976 or 204     — to — ལྕགས་མོ་ཡོས་ལོ་ (female Iron-Hare) 1358 or 977 or 205

Births

• March 17 – Emperor Shijō of Japan (died 1242)
• Guo Shoujing, Chinese astronomer and mathematician
• John de Warenne, 7th Earl of Surrey (died 1304)
• Roger Mortimer, 1st Baron Wigmore (died 1282)

Deaths

• April 6 – William Marshal, 2nd Earl of Pembroke
• June 13 – Anthony of Padua, Portuguese saint (born 1195)
• November 6 – Emperor Tsuchimikado of Japan (born 1196)
• November 17 – Elisabeth of Hungary, daughter of Andrew II of Hungary and saint (born 1207)
• Abd-el-latif, Arab physician and traveller