William now makes his way to London. It was here in London that William the Conqueror had the Tower of London constructed. Its construction was supervised by Bishop Gundulf of Rochester Cathedral, chamberlain of Lanfranc, a talented military engineer who built many Norman fortifications and went on to become the Father of the Corps of Royal Engineers. Other castles built by Gundulf included Rochester castle, Colchester castle and the White Tower of the Tower of London. After the surrender of the men of London, William was now in a position to be crowned King of England.