He gave some support to the king's forces during the Civil War (see J. R. Phillips, Civil War, ii, 154-7), but he virtually retired from public life until the Restoration. It is said that he helped the Parliamentarians to capture Aberystwyth castle in 1646 (Cambrian Register, i, 166). That cannot be proved. He was listed among the ‘delinquents’ on 29 June 1648. His own testimony in 1660 was that he was fined and his house ‘totally plundered to his greate losse’ (S. P. Dom., Charles II, 29/8, 126; see also Cambrian Quarterly Magazine, i, 61). In 1660, he was appointed steward of Mefenydd and four other Crown lordships in Cardiganshire. The earl of Carbery made him one of his deputy-lieutenants for the county. Some Welsh matters came to his attention in Parliament. When a dispute arose concerning an election in Caernarvon town, he was put on the committee to examine the problem, because he knew ‘the ancient true Celtique or Brittish tongue’ (Jnl. of Sir Simonds d'Ewes, ed. Notestein, 455). In 1662, he was one of three nominated to discuss the suitability of translating the new Prayer Book into Welsh (Commons Jnl., viii, 409). Welsh history and antiquities interested him. As one of the executors of Selden's will, he had access to that scholar's priceless library. He retained (see under Field, Theophilus) the manuscript of the ‘Book of Llandaff’ and lent it to Rowland Vaughan, Hengwrt, to transcribe (see E. D. Jones in N.L.W. Jnl., iv, 123). In one of his most noteworthy opinions, he held that the West-minister courts could not issue final process into Wales (Reports, 395). His authority was sufficient to safeguard the Welsh courts for a period. He based his argument on the position of Wales in the Middle Ages and, in his belief, the situation was unchanged in this respect by the Acts of Union of Henry VIII. As late as 1745, his arguments were effectively used in the case of Lampley v. Thomas, when it was ruled that writs of ‘latitat’ could not issue into Wales (English Reports, 1 Wilson, 193). In R. v. Athos, judge Fortescue suggested that ‘…he being a native of Wales, might be prejudiced in favour of his country’ (English Reports, 8 Modern, 145).

The Crosswood estate grew substantially under his administration. At the beginning of his career he bought lands worth £4,300 in Cardigan, and lands in Montgomeryshire at the end of his life. The estate was transferred intact to his only son, Edward. His wife, Jane (Stedman), survived him. They had also two daughters, Anne and Lucy. There are two oil portraits of the chief justice in Wales, one at Gwysaney and the other on loan to the N.L.W.