The White Tower, which gives the castle its name, was built by William the Conqueror from 1078 to 1097. Over the centuries it has served as a fortress, a palace, and a prison. The Tower was originally built as timber Motte and Bailey castle shortly after the Norman Invasion in 1066 but the timber structure was soon replaced by the massive stone keep..... a keep being the strongest and securest part of a castle. This was intended to protect London from invasion, probably by the Vikings who had penetrated the Thames as far as Reading in 870. It is almost 90 feet high and the walls range from 11 feet to 15 feet thick. The tower's name came about during the reign of Henry III (1216-72) when he followed contemporary fashion in Europe to whitewash prestigious buildings. This practise was discontinued by the mid 17th century.
During its time as a prison its inmates included several French royalty, and King Richard II who abdicated there in 1399. The tale of the Princes in the Tower is the most famous story of the castle. When Edward IV died in April 1483 his 12-year-old son was declared King Edward V. Richard the Duke of Gloucester was declared Lord Protector as the prince was too young to rule. He and his younger brother Richard were then confined to the White Tower. The princes were last seen in public in June 1483. It is thought the most likely reason for their disappearance is that they were murdered shortly after that. The Duke of Gloucester was then proclaimed King Richard III in July. In 1674, during the the demolition of an entrance forebuilding, bones belonging to two children were discovered beneath the stairs. Assuming that they belonged to the Princes in the Tower, the remains were re-interred in Westminster Abbey.
The White Tower is a Grade I listed building, and is one of the most important historic buildings in the world.