Why did William the Conqueror where a crown?

What type of army did the US have in the War of 1812? How did noblemen spend free time in ancient Egypt? What was the cause of the development of feudalism and monarlism? What were Jean Piaget's most notable contributions to psychology? Why is the Declaration of Independence considered to be a persuasive argument? Is it Peter van daan of Peter van pels? Why did the Ancient Greeks and Ancient Egyptians worship their Gods? During the Vietnam war us troops had the advantage of what? Who was the first successor of Augustus? What where the three ways in which the first nations people had to adapt their ways after the arrival of the French? What deeds are hatshepsut and akhenenaten best known for? At the end of WW IIGermany was forced to accept all blame for that war by signing the Treaty of Versaille. Why would the people of Germany consider this to be unfair? When did Edith Schwalb die? What did the feudal system protect medieval European society from? How much did a Japanese newspaper cost in 1945? How many Americans had no job during great depression? What was the age of The Victorian era also known as? What did the settlers who migrated to western America want from the American Indians? How have the three ladies helped Lily Daw in the past? What was the weakness of articles of federation?

Why did William the Conqueror where a crown?