Saint Leander of Seville (Cartagena, c. 534–Seville, 13 March 600 or 601), brother of the encyclopedist St. Isidore of Seville, was the Catholic Bishop of Seville who was instrumental in effecting the conversion to Catholicism of the Visigothic kings Hermengild and Reccared of Hispania (the Iberian Peninsula, comprising both modern Spain and Portugal).