A family of saints
Leander was the eldest of four children who would all come to be venerated as saints. His brother Isidore succeeded him as Bishop of Seville and became one of the most influential encyclopedists of the early medieval West; his brother Fulgentius became Bishop of Astigi; and his sister Florentina entered the monastic life, with tradition crediting her oversight of a large number of convents and nuns.
Their father, named Severianus, was a citizen of Carthago Spartaria, and the family moved to Seville around 554. Leander's own monastic formation and the school he founded at Seville helped shape the learning of his siblings, Isidore most of all.
Conversion of the Visigoths
The Visigothic kings of Spain were Arians, holding the teaching condemned at Nicaea, while much of their subject population held the catholic faith. As Bishop of Seville, Leander worked to bring the ruling house to Orthodoxy. He supported the conversion of Prince Hermenegild, assisted in part by Hermenegild's catholic wife Ingunthis, and for his activity he was exiled by King Liuvigild and fled to Constantinople.
After his return, Leander succeeded in winning over Liuvigild's successor, King Reccared. His labors came to fruition at the Third Council of Toledo, which assembled in May 589 with seventy-two bishops. King Reccared made a public confession of faith, anathematized Arius, and accepted the councils of Nicaea, Constantinople, Ephesus, and Chalcedon. Leander, who had organized the council and served as its president, delivered the closing homily preserved as the Homilia de triumpho ecclesiae ob conversionem Gothorum, celebrating the conversion of the Goths.
Reform of worship and writings
Leander reformed the worship of the Spanish Church, introducing the recitation of the Creed into the liturgy as a confession of the faith against Arianism. Upon his return from Toledo he also convened a synod at Seville.
His surviving writings include a monastic rule composed for his sister, the De institutione virginum et contemptu mundi, and the festal homily delivered at the close of the Third Council of Toledo. He maintained a correspondence with Pope Gregory the Great, whom he had befriended in Constantinople.
Veneration
Leander is venerated in both the Eastern Orthodox and the Roman Catholic Churches as a pre-schism Western saint. His principal feast is kept on 27 February; other dates of commemoration include 13 March, the day of his repose, and 13 November in Spain.
