Like Weobley Castle on the northern coast of the Gower Peninsula , Oxwich Castle is actually a fortified Tudor manor house. Built upon, and incorporating the 14th century Castle in which he was born, Sir Rhys Mansel constructed this extensive mansion in the first half of the 16th century.
Sited close to the treacherous shore of Oxwich Bay, the Mansel family found many an opportunity to gain advantage of their proximity to the beach by being the first to plunder the treasures of the numerous sailing vessels that wrecked themselves on the coast here.
However, such eager salvaging brought disaster upon the family when, on 27th December 1557, Sir Rhys Mansel took possession of the riches from a certain French trading ship that had come to grief off Oxwich Point during a gale. The salvage rights to this vessel, to some extent, also belonged to a Sir George Herbert, one of the most important and powerful men of Swansea at the time, and he and his men soon descended upon Oxwich Castle to forcibly argue their rights on the matter. Fearing that the ensuing argument, between Herbert and his men and Mansel and his own, would turn bloody, Sir Rhys Mansel's daughter, Anne, rushed outside the castle to part the two sides. However, as she intervened, she was struck by a stone thrown by Sir George's angered servant and fell to the ground bleeding from her head. This episode resulted in her death six days later. Sir Rice Mansel, took his case to the Star Chamber, which imposed heavy fines on Sir George and his men. They were also ordered to return the salvaged goods and to repair all damage caused by the fracas. Additionally the servant stood trial for his part in Anne Mansel's death.
However, as far as the Mansel family were concerned justice had not been done. The court decided to pardon the stone-throwing servant and Sir George craftily avoided paying his fine, as he decided to put all his possessions into trust with his wife as beneficiary. By the time of his death in 1570 he had managed to avoid paying the sum owed. The bitter feud between the Mansels and the Herberts lasted for many years until Oxwich castle was abandoned by the Mansel family in the late 16th century for their new residence at Margam. The building was leased out to tenant farmers who inhabited the smaller south wing, whilst the large east block fell into ruin.
The site is presently conserved and maintained by CADW - Welsh Historic Monuments.