Not sure why its Will the Conkerer (as Peterpedant might call him) .... yes he came to the English shores and won battle of Hastings to become hink... but why Gloat? Did he officially call himself William The Conquerer (that would be gloating) ... or was that title just give to him later by historians
William III arrived with a fleet of 450 ships. William IV was called the Sailor King as he'd been in the navy for 10 years. I wouldn't swear either of them did any gloating anywhere, though. Do they have to be British kings?