what is the bishop who built the castle known for?
He was the ordinary of the Church of England Diocese of Rochester.
Bishop of Rochester
The Bishop of Rochester is the ordinary of the Church of England Diocese of Rochester in the Province of Canterbury.

when was rochester castle built? UNANSWERABLE who built it? Gundulf, Bishop of Rochester which kings had the possession of the castle? King John and his son Henry what are its notable architectural features? Little is known about the design of the first castle and Gundulf's castle was enclosed by a stone wall.
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Bishop of Rochester [SEP] Introduction
The office was created in AD 604 at the founding of the diocese in the Kingdom of Kent under King Æthelberht.