On This Day

Year in History

Explore the major historical events, famous births, and notable deaths that occurred in the year 421. This year saw 3 significant events.

5th Century420s

421 Timeline

  1. Aelia Eudocia Athenais of Athens marries Eastern Roman Emperor Theodosius II

    Aelia Eudocia Augusta (Ancient Greek: Αιλία Ευδοκία Αυγούστα; c. 400 – 460 AD), also called Saint Eudocia, was an Eastern Roman empress by marriage to Emperor Theodosius II (r. 408–450).

  2. Flavius Constantine becomes Co-Emperor as Emperor Constantius III of the Western Roman Empire with Honorius

    In modern historiography, the Western Roman Empire was the Roman Empire's western provinces collectively during any period in which they were administered separately from the eastern provinces by a...

  3. City of Venice is founded, at noon on a Friday

    City of Venice is founded, at noon on a Friday

Events

Frequently Asked Questions

What happened in 421?
In 421, there were 3 significant historical events. Notable events include Aelia Eudocia Athenais of Athens marries Eastern Roman Emperor Theodosius II, Flavius Constantine becomes Co-Emperor as Emperor Constantius III of the Western Roman Empire with Honorius, City of Venice is founded, at noon on a Friday.

People in 421

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