Martyn’s father was an illiterate yeoman from Strelley, about five miles west of Nottingham, who bequeathed him £30.
Martyn’s connection with the Strelleys brought him into contact with the Byrons of Newstead, one of the most important families in Nottinghamshire. By 1607 he was a trustee for the Byron estate, in which capacity he was mentioned in the Byron estate bill, which was laid before Parliament in 1610. Martyn was also connected to Sir Philip Stanhope, later 1st earl of Chesterfield, from whom he rented the manor of East Stoke, near Newark. As tenant of this property he was involved in a dispute with Sir John Holles* in 1613 over the profits of the manor.
Martyn was one of the signatories to Nottingham’s election return of 1624, which suggests that by then he was one of the town’s freeman. Elected himself to the first Caroline Parliament after the corporation agreed to elect freemen rather than outsiders, he took no known part in debate or committee. The town subsequently employed him on legal business in 1626.
Martyn drafted his will on 22 Sept. 1627, in which he bequeathed £300 to each of his two unmarried daughters as portions, which money was to be paid out of debts owed to him by members of the Nottinghamshire gentry, including Sir John Byron* and Sir Percival Willoughby*. He left his colleague in the 1625 Parliament, Robert Greaves, money for a memorial ring and appointed Byron’s brother-in-law, Sir Thomas Hutchinson*, one of his executors. In accordance with his will he was buried on 3 Oct. 1627 in St. Peter’s, Nottingham.
