1091

1091 (MXCI) was a common year starting on Wednesday of the Julian calendar, the 1091st year of the Common Era (CE) and Anno Domini (AD) designations, the 91st year of the 2nd millennium, the 91st year of the 11th century, and the 2nd year of the 1090s decade. As of the start of 1091, the Gregorian calendar was 6 days ahead of the Julian calendar, which was the dominant calendar of the time.

Millennium:	2nd millennium
Centuries:	10th century – 11th century – 12th century
Decades:	1060s  1070s  1080s  – 1090s –  1100s  1110s  1120s
Years:	1088 1089 1090 – 1091 – 1092 1093 1094

1091 in other calendars

Gregorian calendar	1091 MXCI
Ab urbe condita	1844
Armenian calendar	540 ԹՎ ՇԽ
Assyrian calendar	5841
Balinese saka calendar	1012–1013
Bengali calendar	498
Berber calendar	2041
English Regnal year	4 Will. 2 – 5 Will. 2
Buddhist calendar	1635
Burmese calendar	453
Byzantine calendar	6599–6600
Chinese calendar	庚午年 (Metal Horse) 3787 or 3727     — to — 辛未年 (Metal Goat) 3788 or 3728
Coptic calendar	807–808
Discordian calendar	2257
Ethiopian calendar	1083–1084
Hebrew calendar	4851–4852
Hindu calendars
- Vikram Samvat	1147–1148
- Shaka Samvat	1012–1013
- Kali Yuga	4191–4192
Holocene calendar	11091
Igbo calendar	91–92
Iranian calendar	469–470
Islamic calendar	483–484
Japanese calendar	Kanji 5 (寛治５年)
Javanese calendar	995–996
Julian calendar	1091 MXCI
Korean calendar	3424
Minguo calendar	821 before ROC 民前821年
Nanakshahi calendar	−377
Seleucid era	1402/1403 AG
Thai solar calendar	1633–1634
Tibetan calendar	阳金马年 (male Iron-Horse) 1217 or 836 or 64     — to — 阴金羊年 (female Iron-Goat) 1218 or 837 or 65

Roger I of Sicily (r. 1071–1101)

Events

By area

Europe

• King William II of England invades Normandy.
• Ladislaus I of Hungary occupies Slavonia.
• King Stjepan II of Croatia, the last member of the Trpimirović dynasty, died without leaving anyone to inherit his thrown and title.

British Isles

• October 17 – London Tornado of 1091: A T8/F4 tornado is recorded in St Mary-le-Bow of London, England; the storm destroys London Bridge.
• Henry, the third son of William the Conqueror, is forced to give up his property of Cotentin in Normandy after his two older brothers, William Rufus and Robert Curthose, make a peace agreement.
• King Malcolm III of Scotland makes an unsuccessful attempt to invade English territory, but is finally forced to give a public statement of allegiance to King William II of England.
• Cardiff Castle is built.

Mediterranean

• April 29 – Battle of Levounion: The Pechenegs surround and attack Constantinople, but are defeated so completely by Emperor Alexius I that they are completely eliminated.
• February; With the taking of Noto, the Normans complete the 30 year long takeover of Sicily from the Islamic rulers.
• The Islamic Abbadid dynasty ruling in Spain falls when the Almoravids storm Seville. Faced with this new threat, the king of Badajoz, al-Mutawakkil ibn al-Aftas, got the support of Castile in exchange for the Muslim positions on the Tagus river — Sintra, Santarém and Lisbon.
• Roger Guiscard takes Malta.

By topic

Religion

• Athanasius VI bar Khamoro becomes Syriac Orthodox Patriarch of Antioch.

Deaths

• June 17 – Dirk V, Count of Holland
• July 5 – Abbot William of Hirsau
• August 25 – Sisnando Davides, military leader
• December 19 – Adelaide of Susa, margravine of Turin
• date unknown –

Robert D'Oyly, first Lord of Oxford Castle