The first castle on the Castell Coch site was probably built after 1081, during the Norman invasion of Wales. It formed one of a string of eight fortifications intended to defend the newly conquered town of Cardiff and control the route along the Taff Gorge. It took the form of a raised, earth-work motte, about across at the base and on the top, protected by the surrounding steep slopes. The 16th-century historian Rice Merrick claimed that the castle was built by the Welsh lord Ifor ap Meurig, but there are no records of this phase of the castle's history and modern historians doubt this account. The first castle was probably abandoned after 1093 when the Norman lordship of Glamorgan was created, changing the line of the frontier.