Who Was William The Conqueror?

William the Conqueror conquered England in 1066, by winning the Battle of Hastings against King Harold and then suppressing subsequent revolts, and he ruled the country as William I until 1087.  He was also the Duke of Normandy, in France, from 1035 to 1087.  

William was born illegitimate in Normandy in 1027 or 1028.  He was the greatnephew of  Queen Emma, wife of the English kings Ethelred the Unready and later King Canute.  He succeeded his father to become Duke of Normandy at a young age.  In 1053 he married his cousin Matilda of Flanders, with whom he had ten children including Robert of Normandy, William Rufus - his successor as King of England - and Henry, his youngest son, who also became King of England, Henry I.

The many innovations initiated by William I during his reign of England included the famous Domesday Book, a survey (like a census) of England's productive capacity.  He also had many castles built across the country, including the Tower of London, in order to suppress rebellion.  He died aged 59 in 1087 from injuries sustained falling off a horse at the Siege of Mantes.