Now home to the British Crown Jewels, the Tower of London was built by William the Conqueror in 1078. It served as a prison from 1100 to the mid twentieth century. This has led to the phrase “sent to the Tower”, meaning imprisoned. Famous prisoners include Sir Thomas More, King Henry VI, Anne Boleyn and Catherine Howard (wives of King Henry VIII) and Rudolph Hess. Today the Tower of London is one of the most popular London tourist attractions.