Nothing had been seen like it in England before.Today the medieval defences remain relatively unchanged.Securing the City was therefore of the utmost importance to William.The ditch was intended to flood naturally from the river, although this was not a success.Like Longchamp, John had to cope with frequent opposition throughout his reign.A new wall was also built enclosing the west side of the Inmost Ward.On both occasions the King fled to the Tower of London.It was surrounded by a moat, this time successfully flooded by a Flemish engineer, John Le Fosser.New royal lodgings were included in the upper part of St Thomas’s Tower.Almost all these buildings survive in some form today.