Leander of Seville was a 6th-century Hispano-Roman prelate who served as the Bishop of Seville. Born in Cartagena to an elite family, he became a Benedictine monk before his appointment to the episcopacy. He is most recognized for his pivotal role in converting the Visigothic royalty, including King Hermenegild and his successor Reccared, from Arianism to Catholicism. A scholar and influential leader, he established a renowned school of learning and played a central role in the Third Council of Toledo, which officially ended Arianism in the region.