Edward the Confessor died in 1066, and 4 other people decided that they were eligible for the English crown
The first contender was Edgar the Atheling. He was Edward's nephew. At 14 he went into battle, and was then elected king by the Wilton. His nominal rule laster 2 months, before he fled to Scotland in 1068
The second contender was Harold Godwinson. He was not a royal and his mother had some sort of disallowed relationship with King Cnut. He won many battles for England as he grew older. He was eventually killed by William
The third contender was William Duke of Normandy. He was described as being a good ruler of Normandy. He had a good relationship with England, and he was also a s distant cousin of Edward, even though he lived in France. William and his wife Matilda dedicated their daughter to the church to ensure success. He carried a Papal flag at the front of his army. His invasion was a crusade.
The final contender was Harold Hardrada. He was born in 1015. He was wounded in battle, and fled to Russia. In 1045 he returned to Norway, and shared the throne with his nephew Magnus. Harold only really wanted to be King of England so that he could have more money and power.
The Battle of Hastings was between William Duke of Normandy/ William the Conquerer and Harold Godwinson. William won, and killed Harold. William became king of England, and since then England has never lost a battle. All the kings and queens of England since have been descendants of William the Conquerer.