These sources claim that he was a monk from Wales[2] who became the Bishop of Dol-de-Bretagne in Brittany during the 6th century, and ended his life on the island of Sark, where he was abbot of a monastery.

[4] After Samson's death, Magloire succeeded him as his chosen successor to the archbishopric, although, having received instructions from a visiting angel, he soon resigned his post to Budoc and withdrew to the island of Sark, where he established a community of 62 monks.

It also argues that Nivo, the owner of Guernsey, asked for Magloire's help to cure his daughter who was deaf and intellectually disabled.

[citation needed] A legend is also told that Magloire had trouble keeping a vow to drink neither wine nor ale, and to fast from all food twice a week.

[9] With an increase in Viking raids in the early 10th century, his relics were transported to Paris by the monks, where Hugh the Great granted them land to establish a new monastery.

In 1572, Catherine de' Medici decided to use the site as a home for a group of Benedictine monks who had been expelled from their abbey of Saint-Magloire.

[citation needed] Vita Sancti Maglorii, a work of uncertain provenance written in Latin, details almost all of the knowledge of Maglorius.