1021

Events

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.

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.

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.