Where did concentric castles come from?

Answer 1

Concentric castles originated in the 12th century, primarily in the context of the Crusades and the military architecture of medieval Europe. They were developed in response to the need for more defensible structures, featuring multiple layers of walls, with an inner and outer curtain wall that provided enhanced protection against siege warfare. The design allowed defenders to retreat to the inner walls while maintaining the ability to defend against attackers from multiple angles. Notable examples include the castles built by the Normans in Wales, such as Caernarfon and Conwy.