The Vaughans appear to have been constantly at feud with the Herberts (qq.v.), which may explain why they provided no members of parliament for Montgomeryshire, and only one sheriff, JOHN ab OWEN VAUGHAN (in 1583); he m. Dorothy, daughter of Howell Vaughan of Glan-llyn, and sister of John Vaughan, who was sheriff of Merioneth in 1594. The son of the sheriff of Montgomeryshire, OWEN, m. Catherine, daughter of Morrice ap Robert, heir of Llangedwyn, by whom he had two sons, JOHN (Inner Temple, 1606) and Sir ROBERT, who m. Catherine, daughter of William, 1st lord Powis.

The family became extinct in the male line with Sir Robert, and Llwydiarth and Llangedwyn were carried by his daughter Eleanor to her husband, John Purcell of Nantcribba, and by their daughter to her husband EDWARD VAUGHAN of Glan-llyn and Llwydiarth, sheriff of Montgomeryshire, 1688, and Member of Parliament for the Montgomery boroughs, and subsequently for fifty-eight years for the county, and great-grandson of the sheriff for Merioneth of 1594.

The combined estates of Llwydiarth, Llangedwyn, and Glan-llyn were again carried by Anne, daughter and heiress of Edward Vaughan, to her husband Sir Watkin Williams Wynn (see under Wynn family, Wynnstay), 3rd bart. of Wynnstay, whose mother, Jane Thelwall, heir of Plas-y-ward, was herself fifth in descent from John Owen Vaughan of Llwydiarth (above).

In Mont. Coll., xiv, is an illustrated article on the thirty armorial shields originally on the Vaughan pew in the church of Llanfihangel-yng-Ngwynfa, Montgomeryshire, later transferred to Wynnstay chapel. The same volume also contains a drawing of Llwydiarth (now demolished), taken from the duke of Beaufort's ‘Progress’ in 1684 [see Dinely].