Years: 421 422 423 424 - 425 - 426 427 428 429

Decades: 390s 400s 410s - 420s - 430s 440s 450s

Centuries: 4th century - 5th century - 6th century

Events

• October 23 -Valentinian III becomes western Roman emperor.
• Aetius leads an army into Italy to support the self-proclaimed emperor Joannes.
• Last known usage of Demotic.
• The Sanhedrin is disbanded by the Roman Empire.
• Buddhism begins to spread to Southeast Asia.

Births

• Zu Chongzhi, Chinese mathematician

Deaths

• October 10 - Atticus, Patriarch of Constantinople
• Joannes, usurper in the western Roman Empire.