As part of Henry III's expansion of the castle perimeter a land gate was build on this site. It is reported, however, that on the night of 23 April 1240 (St George's Day) the gate collapsed, followed exactly a year later by part of the nearby curtain wall. On both occasions the ghost of Thomas Becket (the Archbishop of Canterbury murdered in 1170, and a Constable of the Tower) was said to have been seen beating the ground with his crozier. The gate was replaced in 1281 by the present tower when Edward I created a new land entrance to the south-west.
Originally only two storeys high, the tower provided suitable accommodation for aristocratic prisoners and their retinue of servants. One such was Thomas de Beauchamp, Earl of Warwick, Imprisoned there in 1397 for treason against Richard II, and after whom the tower is named.
It is hard to contemplate the boredom that the prisoners must have endured and this perhaps accounts for the inscriptions found here (and others brought in from elsewhere within the Tower), which number eighty-seven in all.