The fortifications of Kingston upon Hull consisted of three major constructions: the brick built Hull town walls, first established in the early 14th century, with four main gates, several posterngates, and up to thirty towers at its maximum extent; Hull Castle, on the east bank of the River Hull, protecting Hull's river harbour, constructed in the mid 16th century and consisting of two blockhouses and a castle connected by a curtain wall; and the later 17th century Citadel, an irregular triangular, bastioned, primitive star fort replacing the castle on the east river bank.
The town with Citadel in 1786. Also shown is the first town dock on the line of the north walls, and the western walls and Bush Dike. (survey by A. Bower)