Martin represented the third generation of a prominent Exeter merchant family which supplied the city with six mayors and a recorder.
Martin had already held all but the most senior positions in Exeter’s corporation when he was elected in 1614 to represent the city in Parliament. As a novice Member he made little impact on the Commons’ proceedings. Indeed, he may have been confused with his brother Richard, a notable figure in the previous six sessions, since the only committee to which he was personally named was to help draft the bill for the repeal or continuance of expiring statutes, a task normally assigned to lawyers (8 April). He was also appointed ex officio as an Exeter burgess to five legislative committees, whose subjects included the new pier at Axmouth, Devon, and problems caused by weirs (21 May). Martin presumably drew on his own recent experience of the shrievalty when, on 14 May, he used his only recorded speech to attack the conduct of the disputed Cambridgeshire election by that county’s sheriff. It is not known whether he was present in the Commons three days later to witness his brother’s ill-advised outburst on behalf of the Virginia Company, and he certainly took no part in the subsequent debates on how to punish such outspokenness.
In November 1618, early in his term as mayor of Exeter, Martin travelled to London to prove his brother Richard’s will. Instructed to dispose of the childless lawyer’s assets, he apparently acquired some of his lands himself, including Lyndridge barton at Bishopsteignton, Devon.