309

By place

Roman Empire

• The Spanish provinces revolt from the control of Maxentius, acknowledging Constantine the Great as their Emperor.
• A plague that may be related to anthrax spreads across the Roman Empire, causing a drastic decline in the population.

  Persia

• King Hormizd II, Shah of the Persian Empire, dies after a 7-year reign and a power struggle for the succession ensues. He is succeeded by his son Shapur II.

  North America

• The limber pine called Twister begins growing.

  By topic

Religion

• Pope Marcellus I is banished from Rome by the Emperor Maxentius.
• April 18 - Pope Eusebius succeeds Marcellus as the 31st pope, but is himself banished on August 17 to Sicily.