St. Vincent of Lerins (ca. 450)
Commemorated on May 24
He was born in Toul in Gaul (modern-day France); he was the brother of St Lupus, Bishop of Troyes. He served as a soldier, but eventually became a monk at the monastery of Lerins. There he lived out the remainder of his life, and wrote his Commonitorium, an exposition of the true Orthodox faith; it contains the well-know statement that Christians must hold to the Faith that has been believed "everywhere, always, and by all." He reposed in peace.