The White Tower was the original castle keep started by William I in 1070, just 4 years after he won the battle of Hastings. It was located to protect the river approaches to the city but soon became favoured as a royal residence.
The first reference to it by the name of ‘White Tower’ is in 1240 when the brickwork was painted.
After it fell out of fashion as a royal residence, the tower continued to functions a the headquarters for royal and governmental administration.