Charles appointed Holles to the Privy Council on 5 June and made him Custos Rotulorum of Dorset, while he was also one of the thirty-four commissioners appointed to try the regicides in September and October. Created Baron Holles of Ifield in April 1661, he became a member of the Lords, then Ambassador to France in July 1663; this was not a success, since his insistence on strict protocol infuriated the French and Charles resorted to communicating with Louis XIV of France through other parties.