William the Conqueror began building, what is now known as the Tower of London, in 1078. The first buildings were the White Tower and its Norman chapel, which is the oldest church in London. During the next 400 years the garrison was rebuilt, altered and enlarged. Henry II organised the construction of the inner wall which surrounds Tower Green, the White Tower and other buildings. Edward I extended the walled fortress and built Traitor's Gate, Beauchamp and St. Thomas Towers. The Bloody Tower was added in the 14th century.
The Tower is situated on the north bank of the river Thames, at the eastern extremity of London. It contains within its walls twelve acres and five roods. The exterior circuit of the surrounding ditch, is three thousand one hundred and thirty-six feet. On the Tower Hill side the ditch has considerable breadth and depth; and here the view was taken which illustrates this description.