900

Events 
Persian scientist, Rhazes, distinguished smallpox from measles in the course of his writings. Holding against any sort of orthodoxy, particularly Aristotle's physics, he maintained "the conception of an 'absolute' time, regarded by him as a never-ending flow".
 Gyeonhwon formally establishes the kingdom of Hubaekje in southwestern Korea.
 Merchants from southwest Asia and India settle on the east-African coast, trading gold, beads and metal for ivory and slaves.
 Harold I of the Yngling or Scilfing dynasty subdues the petty kings of Norway and conquers the Orkney and Shetland islands.