1021
Year 1021 was a common year starting on Sunday of the Julian calendar.
Events
By place
Europe
- November - Emperor Henry II conducts his fourth Italian military campaign. He crosses the Brenner Pass with a 60,000-strong army, and reaches Verona, where he receives Lombard levies. Henry proceeds to Mantua and then into Ravenna, to spend Christmas there.
- Abd al-Aziz al-Mansur, a grandson of the prominent Andalusian figure Almanzor begins his rule in Taifa of Valencia, a Moorish kingdom in Al-Andalus, ushering in a period of relative stability and prosperity that will last until 1061. Taifa of Valencia gained its independence from the Caliphate of Córdoba in 1010.
Africa
- February 13 - On one of his habitual night rides in the outskirts of Cairo, the Fatimid caliph al-Hakim bi-Amr Allah disappears, most likely assassinated by disaffected palace factions, apparently involving his sister, Sitt al-Mulk.
- March 26 - On the feast of Eid al-Adha, the death of al-Hakim, kept secret for six weeks, is announced, along with the succession of his son, al-Zahir li-i'zaz Din Allah. On the same day, al-Hakim's designated heir, Abd al-Rahim ibn Ilyas, is arrested in Damascus and brought to Egypt.
- The last evidence of indigenous Christian and non-Arabophone culture in Tripolitania is seen.
Asia
- Senekerim-Hovhannes Artsruni, Armenian king of Vaspurakan, surrenders his kingdom to the Byzantine Empire. In return, he receives Sebasteia and becomes governor of Cappadocia.
- Battle of Shirimni, the Byzantine Empire under Basil II defeats the Kingdom of Georgia under Giorgi I at Shirimni, at the Lake Palakazio, modern Lake Çıldır, Turkey
- Hovhannes-Smbat III, King of the Armenian kingdom of Ani, is attacked by his younger brother Ashot IV, and loses much power to him, becoming concurrent king of outlying territories.
- Emperor Rajendra Chola I extends his influence of the Chola Empire to the banks of the Ganges River and invades Bengal.
- Sultan Mahmud of Ghazni appoints Malik Ayaz to the throne, making Lahore the capital of the Ghaznavid Empire.
- The Chinese capital city of Kaifeng has some half a million residents by this year. Including all those present in the nine designated suburbs, the population is over a million people.
North America
- Vikings known to be residing L'Anse aux Meadows on Newfoundland.