1091

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

1091 in various 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) 3788 or 3581     — to — 辛未年 (Metal Goat) 3789 or 3582
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)

Year 1091 (MXCI) was a common year starting on Wednesday (link will display the full calendar) of the Julian calendar.

Events

By place

Byzantine Empire

• Spring – Tzachas, a Seljuk Turkish military commander, establishes an independent maritime state centred in the Ionian coastal city of Smyrna (modern-day İzmir). He proclaims himself emperor (basileus), and concludes an alliance with the Pechenegs in Thrace. Tzachas uses his fleet to blockade Constantinople by sea, while the Pechenegs besiege the capital by land.
• April 29 – Battle of Levounion: Emperor Alexios I supported by his allies defeats the Pechenegs' 80,000 men (including women and children) at the Evros River near Enos (modern Turkey). The Cumans and Byzantine forces fall upon the enemy camp, slaughtering all in their path. The Pechenegs are butchered so savagely, that they are almost wiped out.

Europe

• Spring – King Stephen II, the last member of the Trpimirović Dynasty, dies without leaving an heir after a 2-year reign. War and unrest breaks out in Croatia afterwards. King Ladislaus I of Hungary, on instigation of his sister, Queen Helena, intervenes in the conflict and occupies Croatia. He proclaims himself king, but is contested by the Croatian nobleman Petar Snačić.
• February – Norman conquest of Sicily: The Normans conquer Noto and complete the 30-year-long conquest of Sicily from the Moorish rulers. Duke Roger Borsa (a son of Robert Guiscard) surrenders his share in the castles of Calabria, and receives his inheritance of Palermo. He grants charters to various towns and encourages urban planning in Apulia and Calabria.
• Summer – The Norman invasion of Malta: A Norman fleet led by Count Roger I (Bosso) arrives in Malta. Roger disembarks his army, and besieges the island's capital Medina (modern-day Mdina). The inhabitants negotiate peace terms (by promising paying an annual tribute) and swear an oath of loyalty to Roger. On the way back, the Normans sack the island Gozo.
• July – The Abbadid Dynasty ruling in Al-Andalus (modern Spain) falls, when the Almoravid forces storm Seville. Confronted with this threat, Emir Muhammad ibn Abu Bakr Muhammad al-Aftas of Badajoz obtains the support of King Alfonso VI (the Brave) of Castile, in exchange for the Moorish positions on the Tagus River (Sintra, Santarém and Lisbon).

Britain

• Spring – King William II invades Normandy with a large army. His brothers, Henry and Robert Curthose, mobilizes mercenary forces to resist William during the siege at Mont-Saint-Michel. Henry is forced to surrender his estates of the Cotentin Peninsula in Normandy and signs a peace treaty.
• Summer – King Malcolm III of Scotland invades the north of England, and besieges Durham. The Normans led by William II marches north to oppose the Scots, but a conflict is averted. Malcolm is forced to accept the terms of the Treaty of Abernethy (see 1072) and pays homage to William.
• Cardiff Castle is constructed by Robert Fitzhamon, Norman lord of Gloucester (approximate date).

By topic

Disasters

• October 17 – London tornado: A T8 tornado (roughly equal to an T4 tornado) occurs in London. The wooden London Bridge is demolished and the church of St. Mary-le-Bow is badly damaged.

Religion

• December – Athanasius VI bar Khamoro becomes (against his will) patriarch and head of the Syriac Orthodox Church in Antioch (until 1129).

Births

• September 18 – Andronikos Komnenos, Byzantine prince and general
• December 22 – Jutta von Sponheim, German abbess (d. 1136)
• Hongzhi Zhengjue, Chinese Chan Buddhist monk and writer (d. 1157)
• Matilda of Rethel, French noblewoman and sovereign (d. 1151)
• Tiantong Zongjue, Chinese Buddhist monk and patriarch (d. 1162)
• Wartislaw I (or Warcisław), duke of Pomerania (approximate date)

Deaths

• March 26 – Wallada bint al-Mustakfi, Andalusian female poet (b. 994)
• June 17 – Dirk V, count of Friesland (west of the Vlie) (b. 1052)
• June 29 – Frederick of Montbéliard, margrave of Turin
• July 5 – William of Hirsau, German abbot and music theorist
• August 8 – Altmann of Passau, German bishop and saint
• August 25 – Sisnando Davides, Mozarab military leader
• December 19
  • Adelaide of Susa, margravine of Turin
  • Fujiwara no Tadaie, Japanese statesman (b. 1033)
• Fu Yaoyu, Chinese government official and politician (b. 1024)
• Helena of Hungary, queen of Croatia (approximate date)
• Jordan I (or Giordano), Italo-Norman prince of Capua
• Mac meic Aedh Ua Flaithbheartaigh, king of Iar Connacht
• Robert D'Oyly, Norman nobleman (approximate date)
• Stephen II (or Stjepan), king of Croatia (approximate date)
• Wolfhelm of Brauweiler, German Benedictine abbot
• Zaheer-ul-Daulah Artuk Beg, Seljuk general and governor