Martin was active as a barrister on the Northern Circuit, and gained a reputation for skill. He took silk in 1845. He entered the House of Commons for Pontefract in 1847 as a Liberal, after a closely fought contest. However, he only held the seat until 1850, when he was knighted and appointed a Baron of the Exchequer. He received an LL.D. from Trinity in 1857.
Later life
Martin left the Exchequer bench in 1873, due to deafness, and was appointed a Privy Counsellor on 2 February 1874. He returned to the Middle Temple in 1878. He divided his time between his estate at Myroe, County Londonderry (where he was a justice of the peace and a deputy lieutenant) and his London residence in Piccadilly. He died at the latter in 1883 and is buried in Brompton Cemetery, London.[1]