401


 * This article is about the year 401. For other uses, see 

World

 * The human population reaches 206 million.

Byzantine Empire

 * sends many gifts to the nish chieftain Uldin in appreciation of his victory over the and .  Arcadius then allies himself with the Huns.

Western Roman Empire

 * The begin to attack the northernmost reaches of, causing destruction in the countryside.
 * Roman general leads an extensive campaign against the  in.

Asia

 * arrives in.

Religion

 * — succeeds  as the 40th.
 * Innocent proclaims his universal power over the whole of.
 * The is finalised.

Births

 * , East (d. )
 * , wife of Theodosius II
 * , East Roman Emperor