Born the son of a Welsh noble with an Irish peerage, Vaughan initially entered the House of Commons as Member of Parliament for the Welsh constituency of Carmarthenshire in 1624. He held the seat until 1629, when King Charles I decided to rule without parliament until 1640. Knighted in 1626, he appears to have little interest in politics, and after inheriting the estates and titles of his father in 1634, retired to the life of a country gentleman in South Wales. The outbreak of the English Civil War in 1642 disturbed his peace, and after being courted by both King and Parliament, he declared as a Royalist. He raised troops for the king, and took control of the Southern Welsh counties on behalf of the Crown, for which he was rewarded with titles and responsibilities.