Sweyn I, or Sweyn Forkbeard (17 April 963 - 3 February 1014) was King of Denmark from about 985-3 February 1014 and King of England from 25 December 1013 to 3 February 1014.
Sweyn's father was Harald Bluetooth, King of Denmark. Sweyn invaded England many times between 990 and 1013, when his army took control of London on Christmas day. Sweyn briefly became King of England until he died 40 days later on 3 February 1014 after being hurt in a fall from his horse.