Why was the battle of Hastings fought?

Harold Godwinson and Duke William of Normandy fought the battle of Hastings in 1066 over the crown of England - the winner would get to be king. They were fighting because both of them claimed that they ought to be king after Edward the Confessor, who had died earlier in that year. Harold had been earl of Wessex - an important nobleman in England - during Edward's reign, and claimed that Edward had declared him to be his successor on his deathbed. However, Harold had no blood relation to Edward or the royal family. William, on the other hand, was eligible for the throne because he was a distant cousin of Edward the Confessor, and he claimed that both Edward and Harold had promised that he would be the next king. When Harold took the throne, William was angered and invaded in order to claim the throne which he believed was rightfully is. It is impossible to know whether Harold really did swear an oath to William in 1064, although we know he was in Normandy at that time.When William invaded England he began to burn the countryside in the south of England as part of his invasion, in order to draw Harold into a battle where he could take the crown. As he was invading a foreign country, William needed to draw his enemy into a battle before his army's supplies ran out and he would have been forced to return to Normandy. Harold, who had only just defeated Harald Hardrada, king of Denmark and another claimant to the throne, at Stamford Bridge in the North, was forced to march his army hard to the south in order to defeat William. Not only did he need to stop William from burning his country, but he also needed to defeat him as a rival for his throne; while William lived, there would always be people who supported him as king of England over Harold. For Harold to have a secure reign, he needed to be the only claimant to the throne of England. The two armies met at a place called Battle, just outside of Hastings, both knowing that they needed to fight this battle, and in order to win the throne of England, they needed to win.