Wales - Powys - Welsh Border Castles - Tretower - Tretower Castle was first established by a Norman knight of the Picard family who assisted Bernard de Neufmarche in his conquest of Brycheiniog. The manor continued to be held by the Picard family for many generations, during which time the original timber castle was upgraded. It then passed through several hands, being damaged by Owain Glyndwr whilst garrisoned against him by Sir James Berkeley. By this time the main dwelling was at the Court built nearby, and the castle fell into disrepair.