Montfichet tower possibly originated in the reign of William I, but is not documented until the 1130’s. It was given to the Black Friars in 1275 and demolished soon afterwards.
In addition to his great work of the Tower, the Conqueror caused the founding of two strongholds at the. W. end of the City walls, to overawe, as well as to protect, the town. These were Baynard’s Castle and Montfichet, the latter fortress being built by a Norman named Gilbert de Montfichet, who founded it at the foot of Addle Hill, near to the Carron Wharf. Its W. side was washed by the Fleet stream, the course of which was diverted afterwards ‘to the westward, in order to improve the site of the Dominican, or Slack, Friary.
One account says this castle was destroyed by fire, but Pennant relates that King John, having, in 1213, banished Richard, the son of Gilbert Montfichet, demolished his castle, which, in 1276, was quite pulled down, the materials being used to build the great house of the Dominicans on its site. Pennant says that the City wall on the W. ended on the river in a fort, “which 1 take to have been the Castle of Montfichet:” (Castles Of England, Sir James D. Mackenzie, 1896)