Sir Roger Vaughan, 3rd son of Roger Vaughan of Bredwardine by Gwladys, daughter of Dafydd Gam, was the first of the Vaughans to reside at Tretower. It is said that the residence was a gift to him from his half brother William Herbert, earl of Pembroke, to whom the castle and manor of Tretower had descended by marriage of his father, Sir William ap Thomas, to the widow of Sir James Berkeley, heiress of Tretower. Roger Vaughan enlarged and remodelled the house by the addition of a western range of buildings with a hall. Like all his kindred, Roger Vaughan is found on the Yorkist side in the divisions of his time, but he also was granted a pardon by the Coventry Parliament of 1457. The Privy Council ordered him, with Sir William Herbert and Walter Devereux, to prevent assemblies and the victualling of castles in Wales, 17 Aug. 1460. He was with Edward's forces at Mortimer's Cross, 1461, and it is said that it was he who led Owain Tudor to his execution at Hereford after the battle. He was granted the offices of porter of the castle of Bronllys, forester of Cantrecelly, steward and receiver [of the] lordships of Cantrecelly, Penkelly, Alexanderston, and Llangoed, 15 Nov. 1461, and lands in south-west England, 11 July 1462. He took a prominent part in quelling a rising in Carmarthenshire in 1465, and received grants of the insurgents' manors and estates in Gower and Kidwelly.
By 23 March 1465 he was a knight... He was on commissions of 'oyer and terminer' in Wales and the Marches in 1467 and 1468. In the earl of Warwick's charter to Neath abbey, 24 June 1468, Vaughan as the earl's chancellor at Cardiff is the first witness, and Thomas ap Roger, possibly his son, is described as coroner of Cardiff. The common belief that he fell with his brothers at the battle of Banbury is incorrect. Lewis Glyn Cothi called upon him to avenge that battle, and on 16 Feb. 1470 he was appointed constable of Cardigan castle. After the battle of Tewkesbury, 1471, it is said that Edward IV ordered him to pursue and capture Jasper Tudor, earl of Pembroke, but it was Vaughan himself who fell into the earl's hands, to be summarily beheaded at Chepstow. 1