1017

Europe

• Summer – Melus of Bari, a Lombard nobleman, revolts and is supported by Norman mercenaries at Capua. He marches into Apulia to catch the Byzantine army off-guard. Melus defeats the Byzantines on the banks of the Fortore River and ravages the territory in Apulia.
• Winter – Emperor Basil II ("the Bulgar Slayer") replaces Leo Tornikios with the new catapan Basil Boioannes and sends him reinforcements (including a detachment of the elite Varangian Guard) from Constantinople.

England

• January 6 – Cnut ("the Great") is crowned king of England. In July he marries Emma of Normandy, the widow of Æthelred the Unready, securing his ties with Normandy.
• Cnut divides England into four earldoms: Wessex, Mercia, East Anglia and Northumbria.

Arabian Empire

• Summer – Hamza ibn-'Ali ibn-Ahmad publicly declares the founding of the Druze religion, during the reign of the Fatimid Caliph Al-Hakim bi-Amr Allah.

Africa

• The Sunnis of Kairouan (modern Tunisia) revolt against the Shi'ite Zirid dynasty. The city is quickly retaken and sacked.

Asia

• March – Fujiwara no Michinaga passes the title of regent of Japan (Sesshō) to his eldest son Fujiwara no Yorimichi.
• September
  • Prince Atsuakira of Japan, eldest son of ex-Emperor Sanjō, having been struck by a skin disease and under intense pressure from Michinaga, resigns the title of Crown Prince in favour of his younger brother, Prince Atsunaga who marries Fujiwara no Kanshi, daughter of Michinaga.
  • Michinaga makes a pilgrimage to the Iwashimizu Shrine in Japan accompanied by many courtiers. The travelers divide themselves amongst 15 boats for a floating trip down the Yotogawa River. One of the vessels overturns and more than 30 people lose their lives.
• December 24 – Michinaga is granted the honorary title Daijō-daijin of Japan.
• Rajendra I, ruler of the Chola dynasty (in modern India), conquers Sri Lanka and annexes the island.

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