The son of John Martin (died 1767), a publican and grazier, by his wife Mary King, he was born at Spalding, Lincolnshire, on 15 March 1741.
He was called successively to Kimbolton, Huntingdonshire, Shepshed in Leicestershire where he was an itinerant preacher, and in 1773 to Grafton Street Chapel in London.
[1] In 1798 Martin offended other Baptists by defending the Test and Corporation Acts, and in January 1798 he provoked widespread indignation among English Dissenters by declaring from the pulpit that should the French land in England many of them were quite capable of helping them.
[1] In 1763 Martin became convinced of the duty of believers' baptism and published a pamphlet, suggested partly by his work in London as a watch-finisher, and entitled Mechanicus and Flavens, or the Watch Spiritualised.
His writings included:[1] Joseph Ivimey also credited him with a pamphlet on ‘The Murder of the French King’ (1793).