 It is likely that he joined the "Equites catafractarii Ambianenses", a heavy cavalry unit listed in the "Notitia Dignitatum".As the unit was stationed at Milan and is also recorded at Trier, it is likely to have been part of the elite cavalry bodyguard of the Emperor, which accompanied him on his travels around the Empire.According to his biographer, Sulpicius Severus, he served in the military for only another two years, though it has been argued that these two years, "are in fact not nearly enough to bring the account to the time when he would leave, that is, during his encounter with Caesar Julian (the one who has gone down in history as Julian the Apostate) Martin would have been 45 years old when Julian acceded to the throne, and at the usual end of a military contract.