The future saint was born in Ireland in the 6th century and received his education in the monastery of Bangor. His mentor was Saint Columban. In 590, he set out with twelve companions to Gaul to preach Christianity.
Around 610, the missionaries arrived in Switzerland, where they encountered pagans. Saint Gall destroyed idols and converted the local inhabitants to Christianity. He lived in a new community, strengthening the faith of the converts.
In 612, after an illness, the saint found a secluded place in the mountains, where he asceticized with several monks. Later, a monastery of Saint Gall was founded at this site, around which the city of St. Gallen arose.
In 615, at a gathering of bishops, the saint was elected bishop of Constance, but he declined this honor, proposing the candidacy of his disciple John. He built a temple with twelve chapels and lived in his monastic community until the end of his life, humbly serving the brethren.
The exact date of his death is unknown, but the years 627, 630, 640, and 650 are mentioned. In 680, the first biography of the Venerable Gall was composed. The monastery became a place of pilgrimage, and in 835, a new basilica was consecrated in St. Gallen, where the relics of the saint were transferred.
