John Commin was the son of John and Jane Commin of Moretonhampstead where he was born on 8 March 1774. His parents were members of the Cross or Presbyterian New Meeting in the town. On 4 December 1798 he married Rose (or Rosa) Pollard at Holy Trinity Church, Exeter. Described in his obituary as “for many years a respectable tradesman” in Exeter, John Commin was a salter and cheesemonger with premises in North Street.