 The Welsh Marches had been encastellated from an early date, beginning even before the Conquest.However, the proliferation of castles in Wales dates only from its English conquest, though a few stone castles date from the reign of Llywelyn the Great.Motte-and-bailey castles existed from before the thirteenth century in those parts of Wales which fell under English authority and they spread in south Wales after its conquest, but the most famous encastellation of Wales occurred in the north under Edward I of England (1272–1307).