AD 311

By place

Roman Empire

• April 30 - Emperor Galerius declares on his deathbed religious freedom, and issues his Edict of Toleration, ending persecution of Christians in the Eastern part of the Roman Empire.
• May 5 - Emperor Galerius dies, age 51, from a gruesome disease, possibly bowel cancer or Fournier gangrene.
• Maximinus II divides the Eastern Empire between himself and co-emperor Licinius, and mobilises his army for a campaign in Asia Minor. He recommences the persecution of Christians.
• Maxentius, Roman usurper, reconquers the African provinces from Domitius Alexander.
• Maxentius builds the Circus of Maxentius near the Via Appia. The circus is 513 meters long and 91 meters wide, and offers an accommodation to some 10,000 people.
• December 3 - Diocletianus dies at his palace in Split. Possibly he commits suicide.

  China

• Jin Huaidi, emperor of the Jin Dynasty, is captured at Luoyang. The capital city is pillaged by Liu Cong, ruler of the Xiongnu state, the invaders slaughter 30,000 citizens.

  By topic

Religion

• July 2 - Pope Miltiades succeeds Pope Eusebius as the 32nd pope.
• The Donatist schism occurs in the African church.