In the year 1084...
- Holy Roman Emperor Henry IV takes his revenge upon Pope Gregory VII, who has twice excommunicated him over the issue of lay investiture, by marching his army into Rome, deposing Gregory, and installing Clement III as Antipope, only to have French Norman forces led by Robert Guiscard drive him off and reinstall Gregory. Robert's troops then proceed to plunder the city for three days before Henry returns to drive them off. Gregory flees south with them, leaving Rome popeless until Gregory's death the following year, when he is succeeded with only token resistance from Henry by Victor III.
- The Seljuk Turks recapture Antioch from the Byzantine Empire.
- Seljuk pirate Tsacha sacks the city of Smyrna in Asia Minor.
- Norman crusaders led by Bohemund I defeat the Venitians in a series of naval skirmishes off the coast of what is now Albania, clearing the way for further incursions into the Byzantine Empire.
- Prince of Kiev Vladimir Monomakh plunders and razes the city of Minsk in what is now Belarus.
- Pope Gregory's ally Countess Matilda of Tuscany routs German forces loyal to Henry IV at the Battle of Sobara, retaining her control of crucial passes through the Alps between Germany and northern Italy.
- Saint Bruno founds a monastery in the French Alps at La Grande Chartreuse, giving birth to the Carthusian Order of Catholic monks.
- A team of Chinese historians led by Sima Guang concludes 18 years of effort by completing the monumental Zizhi Tongjian ("Comprehensive Mirror for Aid in Government"), an exhaustive integrated history of China from 403 BC to AD 959.
These people were born in 1084:
These people died in 1084:
1083 - 1084 - 1085