He obtained command of a cavalry regiment in Ireland in 1683, and having received an appointment at court on the accession of James II, he served against the Duke of Monmouth at the Battle of Sedgemoor in July 1685. Having succeeded his grandfather as 2nd Duke of Ormonde on 21 July 1688, he was appointed a Knight of the Order of the Garter on 28 September 1688. In 1688 he also became Chancellor of Trinity College, Dublin and Chancellor of the University of Oxford.