A Short History of Oystermouth Castle
by Gerald Gabb

In about 1106, Henry Beaumont, Earl of Warwick, became the first Norman Lord of Gwyr, or Gower. This included the peninsula, but also a lot more land to the north and east. He built his first castle where Swansea now is, on the bank of the Tawe, and made sure others were put up at Loughor and Pontarddulais to guard his north western boundary. The richest farming land was divided among Henry's followers, and the manor of Oystermouth went to the de Londres family who also held Ogmore and its castle in next-door Glamorgan.

The earliest part of Oystermouth castle - the front part of the central block or keep, may belong to the time of the first William de Londres (died 1126) or his son Maurice. We know that in 1141 he gave the income of his parish church in what was called 'Ostremuwe' to help finance a new priory at Ewenny. His son, another William, was a witness to Swansea's first charter, issued some time before 1184.

The male line of the de Londres family gave out early in the next century, but sometime before this Oystermouth had become a demesne manor - in other words the lords of Gower took it for themselves.

The Lords of Gower