The Tower of London was built by William the Conqueror in 1078 as a castle and palace. Since that time it has expanded to its present size, and is used as an Armoury, a zoo, a royal mint, a prison, and a museum. At the time when it was a prison a lot of people were locked in the Tower for their religious beliefs or suspected treason. Anne Boleyn, Sir Walter Raleigh and Elisabeth the First were shut up there, too. Spies were imprisoned in the Tower during both World Wars. Some of the prisoners were allowed to walk in the grounds, live in comfortable rooms and receive visitors. Many convicted were publicly executed on Tower Hill. They were beheaded with the block and ax, which is kept and shown in the Tower Armoury now. The Jewel House is situated at the Tower. The collection of the Crown Jewels is kept in it. Saint Edward’s Crown, the Imperial State Crown, and the royal sceptre are guarded there. Saint Edward’s Crown is used for the coronation ceremonies. 3000 precious jewels are contained in the Imperial State Crown. In 1671 a daring attempt was made to steal the Crown Jewels by a man named Captain Blood.