(Kent) stands above the river Medway whose crossing it controlled. The present castle was begun by Gundulf, bishop of Rochester, for William Rufus 1087–9. It was transformed by the addition of a keep built 1127–40, after Henry I had granted the castle to the archbishop of Canterbury. The defensive strength of the castle was demonstrated in 1215 when rebel barons held it against King John. The royal forces took the castle only after they managed to undermine the south‐east angle tower.
Subjects: British History.