Isidore was born in Seville Spain in 560 and succeeded his elder brother Leandro as bishop of Seville around the year 600. He did much to consolidate the Spanish Church by calling councils, founding religious houses and fighting Arianism. He was a prolific author; his last work, Etymologies, was an encyclopedia which continued to be used throughout the Middle Ages. He died in 636 and was declared a Doctor of the Church in 1722. – CTS New Daily Roman Missal 2012, p 2626; Vatican II Weekday Missal 1975, p 1646.