William de Braose, 3rd Lord of Bramber

1135–1179) was a 12th-century Marcher lord who secured a foundation for the dominant position later held by the Braose family in the Welsh Marches.

In addition to the family's English holdings in Sussex and Devon, William had inherited Radnor and Builth, in Wales, from his father Philip.

He became a trusted royal servant during the subsequent reign of Henry II, accompanying the king on campaigns in France and Ireland.

[3] In about 1155, he also inherited through his mother's family one half of the honour of Barnstaple in Devon, paying a fee of 1,000 marks for the privilege.

When Archbishop Theobald of Canterbury was asked by Pope Adrian IV to inquire into the background of a certain Walter, canon of St Ruf, his reply, dated 1154/9 read: The facts which you demand need but little enquiry; for they shine so brightly in themselves that they cannot be hid; so great is the brilliance of his noble birth and the glory of all his kin.

[7] Empress Maud, the only legitimate living child of Henry I, landed in England in 1139 in an attempt to press her claim to the monarchy.

William was present as a witness when three charters were issued by Stephen at Lewes dated to the years 1148–53,[9] therefore, it appears that he remained loyal to the king until the Treaty of Wallingford ended the hostilities.

[1] King Henry withdrew his favour from the family after William's son organised the murder of Seisyll ap Dyfnwal and other Welsh princes at Abergavenny in 1176.