Answer:
The Duke of Normandy (in France) William, had been promised the throne of England by King Edward the Confessor, who had lived in Normandy in exile before becoming King of England. When Edward died, King Harold, of the powerful Godwin family, was nominated King by the Wittenagemot. He was crowned by the Archbishop.
Immediately, King William laid claim to the throne of England and began to prepare for its invasion. He amassed a fleet of dozens of longboats and 7 000 soldiers. He then proceed to invade England by crossing the Channel, a feat of arms that is still admired today.
King Harold had already defeated King Hardrada of Norway who was also trying to invade England from the North. He then marched south to square it with William. Unfortunately, he was killed by an arrow in the eye (which might be a legend) and William won a sound victory at Hastings. William was later crowned as William I at Westminster Abbey.
Hope this Helps
