In the year AD
- The Khitans invade northern China, marking the beginning of the end of the great Tang dynasty.
- A uprising led by Khuc Thua Dzu against Chinese rule secures Vietnamese independence, which lasts ten centuries until the French arrive in 1862.
- Ethelwald returns to England with his Danish allies to continue his war against King Edward the Elder, overrunning Mercia, East Anglia, and Northumbria before being slain by Edward.
- The Abbassids recapture Palestine and Egypt from the Tulunids, ending the Tulunid dynasty of Egypt that had broken away from the Abbassids under Ahmed Ibn Tulun in 868.
- Navarre throws off the yoke of the Moors, becoming a Christian kingdom under Sancho I.
- The last of the great Mayan cities are abandoned (905 is the last date carved into the ball courts at Uxmal).
- The Japanese Emperor orders the publication of the Kokinshu or Kokin Wakashu (Collection of Ancient and Modern Poems), an anthology of 1,111 poems.
- Persian astronomers at Isfahan discover the Andromeda Galaxy.
- A large comet with a long red tail is sighted in many parts of the world, and widely held to be an omen of doom.
These people were born in 905:
These people died in 905:
904 | 906