Appointed Lieutenant-General and Master of the Ordnance in 1680, he served as Secretary of State in Scotland under James II and VII from 1684 until 1688. He was created Viscount of Melfort and Lord Drummond of Gillestoun in 1685, and a member of the Privy Council of England in the same year, and Earl of Melfort, Viscount of Forth and Lord Drummond of Riccartoun, Castlemains and Gilstoun in 1686, all titles in the Peerage of Scotland. In 1687, he was appointed one of the founder Knights of the Order of the Thistle