The historian John Hale considered the original castle to form a transitional design between older medieval English designs and the newer Italian styles of defence.[75] Like its sister castles along the Downs, Deal suffered from design problems: it needed too many guns to ever be fully equipped; its curved surfaces were vulnerable to attack; and despite attempts to keep the walls low and thick, its relatively high profile, driven by the requirement to support several tiers of defences, exposed it to attack.[76]