Rochester Castle stands on the east bank of the River Medway in Rochester, Kent, South East England. The 12th-century keep or stone tower, which is the castle's most prominent feature, is one of the best preserved in England or France. Located along the River Medway and Watling Street, Rochester was a strategically important royal castle. During the late medieval period it helped protect England's south-east coast from invasion. The first castle at Rochester was founded in the aftermath of the Norman Conquest. It was given to Bishop Odo, probably by his half-brother William the Conqueror. During the Rebellion of 1088 over the succession to the English throne, Odo supported Robert Curthose, the Conqueror's eldest son, against William Rufus. It was during this conflict that the castle first