Duke William of Normandy won the battle because was well prepared and had a good army. They prepared carefully for the battle. The Normans had knights on horseback who were skilful fighters. William also was skilful and ambitious, and he was determined to be King of England.
There were many factors contributing to the victory of William the Conqueror in 1066. Firstly, the English king Harold was prepared for a Norman invasion many months previously but shortly before it happened, the Vikings unexpectedly invaded in the north and Harold had to march his army up the country, fight them and march back down again before the Normans came.
Secondly, at the Battle of Hastings itself, the English did not have any cavalry where as the Normans did which mean that they had an advantage. During the battle, the English King Harold was wounded and the Normans got scared a retreat which fooled the English soldiers into thinking that they had won. They all broke ranks and ran towards the Normans. Finally Harold was killed and the English lost the Standard and William had won. William was well prepared for the battle because he had more men as well as having more time to prepare. Also, King Harold did not have time to prepare properly for the battle because he had to fight Harold Hadraada and his brother Tostig at Stamford Bridge. Harold had to march his men south fast, exhausting his army. Also that I think he won because he had been talking aboutrelated to the war for over 15 years. His soldiers were well trained and equipped. He had also assembled a fleet of ships operated by an army of 20,000 men. Lastly, he promised titles and land to his followers so that they would fight for him and gets the crown off Harold. One of the factors that made William win the battle of Hastings was that Harold could not wait