1040

Events

• August 14 - King Duncan I is killed in battle against his first cousin and rival Macbeth. The latter succeeds him as Scottish Monarch.
  

  Deaths

• August 14 - Duncan I, king of Scotland
• October 1 - Alan III, Duke of Brittany (poisoned) (b. 997)
  

  See also

• For the U.S. Internal Revenue Service (IRS) form, see Form 1040.