What was the purpose of caerphilly castle being built?
One of Henry III’s most powerful and ambitious barons, Gilbert de Clare, lord of Glamorgan, built this castle in 1270. His purpose was to secure the area and prevent lowland south Wales from falling into the hands of the Welsh leader Llywelyn the Last, who controlled most of mid and north Wales and he had taken Gruffydd ap Rhys (ruler of Uwch-and Is-Caiach) a prisoner.