The Tower of London is a landmark in central London. The White Tower, the square building with turrets on each corner that gave it its name, is the oldest part of the Tower  It was built under William the Conqueror (11th c.) and served as a fortress, then as a treasury, a mint, a prison, and later as a zoo. Famous people were executed here: Sir Thomas More (for refusing to acknowledge Henry VIII as the head of the Church, 1535); Anne Boleyn (Elizabeth's mother, Henry's 2nd wife); Catherine Howard (Henry's 5th wife).