From thepeerage.com:
He was offered a peerage at the accession of King George I but declined. He held the office of Member of Parliament (M.P.) for Dungannon, County Tyrone. He was appointed Privy Counsellor (P.C.). He purchased land in Dungannon, County Tyrone in 1692. He was recognised by Lord Lyon King of Arms as as male representative of the Knoxes of Ranfurley, and matriculated his arms at the Lyons Court as male representative of the Knoxes of Ranfurley on 15 July 1693.
Resigned his Belfast burgesship in favour of Edward Brice, his brother-in-law, in 1697.
Full biography available from
The Dictionary of Irish Biography