On the death of his father, William the Conqueror, William left the Duchy of Normandy to Robert Curthose, the Kingdom of England to his son William Rufus, and 5000 pounds in silver to his son Henry. When William Rufus died, Robert was on a crusade to the holy land, so Henry seized the throne and was accepted as king.

He ruled 1100-1135. When he died without a male heir, his daughter, Mathilda, claimed the throne. At this point in history, England was not yet ready for a queen to rule, so Stephen, Henry's sister's son, was made king.

Reigned 1100-1135. Duke of Normandy 1106-1135.
His reign is notable for important legal and administrative reforms, and for
the final resolution of the investiture controversy. Abroad, he waged several
campaigns in order to consolidate and expand his continental possessions.
Was so hated by his brothers that they vowed to disinherit him. In 1106 he
captured Robert and held him til he died. He proved to be a hard but just
ruler. He aparently died from over eating Lampreys!


http://users.LegacyFamilyTree.com/USPresidents/Royalpresidents.htm says he died on December 11.