what was the reason for this battle?
The  death of the childless King Edward the Confessor in January 1066, which set up a succession struggle between several claimants to his throne.
Battle of Hastings

The background to the battle was the death of the childless King Edward the Confessor in January 1066, which set up a succession struggle between several claimants to his throne. 
when did the battle of hastings start and finish The Battle of Hastings was fought on 14 October 1066. who all fought in this battle? The Norman- French army and the English army. who won? The Norman-French army of William. where did this battle take place? Approximately northwest of Hastings, close to the present-day town of Battle, East Sussex.
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Battle of Hastings [SEP] Introduction
Harold's death, probably near the end of the battle, led to the retreat and defeat of most of his army. After further marching and some skirmishes, William was crowned as king on Christmas Day 1066.