The presence of the monk Martino on the Gallinaria island in 359-360 is securely documented by Sulpicius Severus, the saint's first biographer, who wrote while the bishop of Tours was still alive.
A native of Pannonia, he was born to pagan parents in 316-17 in Sabaria (today Szombathèly, Hungary), the seat of the garrison of the official father of the Roman army, who wanted to call him Martinus ("little Mars"). Following his father, who had been transferred to Pavia, in 328-329 he met a Christian community and enrolled among the catechumens. At 15, pressured by his father and imperial laws, he entered the army as the son of a veteran taking a military oath and was assigned to the imperial guard corps on horseback in Gaul. The most famous episode of his biography is linked to this period: in 338, at the Amiens gate, while carrying out the night watch, he shares his cloak with a poor naked man, giving him the fur lining; also in Amiens, at the age of 22-23, he received baptism. In 356, during a campaign on the Rhine led by the Emperor Constantius II against Alamanni and Franks, Martin refuses to take up arms against the barbarians, claiming to want to leave the militia, and is thrown into prison. The following day, the enemies send an embassy to negotiate peace: the Christians cry out for a miracle and Martin gets his leave.
Leaving the army he goes to Poitiers to bishop Hilary (previously known), champion of Nicene orthodoxy not aligned with the Emperor's Arianism, and stays with him for a while. The bishop would like to incardinate him in his own church by offering him ordination to the diaconate, but the former soldier wants to keep himself free from high-level offices, intending to devote himself to the ascetic life, and ends up accepting the role of exorcist. Therefore proposing to visit his parents, he leaves for Pannonia, where he converts his mother, but not his father; finding the opposition of the Aryan bishops of Illyricum, he is insulted, threatened, flogged in public, and leaves the country. Learning that the bishop Hilary had been exiled to Phrygia, in 358 he stopped in Milan and there he adapted a monasterium, a hermitage, to be understood as an isolated cell of the hermit. But even this solution is short-lived: the Arian bishop Aussentius drives him out.
it is in this context that the exorcist Martino takes refuge in the Gallinaria island: ad insulam, cui Gallinariam nomen est (Sulpicio Severo, Vita Martini 6,5) and leads a monastic life there together with a presbyter companion of the Milanese church. On the island he lives for a few weeks, at most a few months, between 359 and 360, feeding on herb roots until he becomes intoxicated when he feeds on hellebore, a poisonous plant, however overcoming the crisis with prayer (although the ancient sources do not mention the place of residence of the saint on the Gallinaria, it is a widespread tradition that he lived in the cave that currently bears his name).
After learning that Hilary's exile has ended, he wants to join him in Rome, but cannot find him; then he goes to Poitiers, where he is ordained deacon and then a priest, but convinces Hilary to let him lead a hermit life, while dedicating himself to the evangelization of the countryside, still pagan. Hilary grants him a piece of land not far from Poitiers: a wooden cell of a hermit, origin of the monastery of Ligugé, the first example of a monastic foundation in Europe. He is joined by companions and the fame of his miracles spreads.
Chosen by the Christians of Tours as bishop in 370, he prefers to live as a monk using a cell adjacent to the cathedral, and wanting to isolate himself more from the crowd that rushed to him, he set up a hermitage two miles from the city, in Marmoutier (maius monasterium), where the ascetic bishop Martino has a cell made of pieces of wood joined together and about eighty disciples adapt for themselves, in the rock of the mountain above, the cavities as their own shelter. Continuing to lead a monastic life, he was an apostle of the countryside in Gaul and a point of reference for the believers of Gaul and other regions until his death in Candes on November 8, 397. His body was transported to Tours, where the November 11, his funeral was celebrated and he was buried.
The cultured lawyer Sulpicius Severus (360-420), an admirer of the monk Martin, wrote his biography to defend him from the attacks of a part of the high clergy of Gaul, who did not look favorably on this pastor with a military past and above all austere conduct . Gregory of Tours (538-394) made him the national hero by writing the Historia Francorum and I miracoli di S. Martino.