Isidore of Sevilla, Saint

(born c. 560, Cartagena or Sevilla, Spain—died April 4, 636, Sevilla; canonized 1598; feast day April 4) Spanish prelate and scholar, last of the Western Fathers of the Church. He became archbishop of Sevilla c. 600 and presided over several councils that shaped church policy, including the fourth Council of Toledo (633). He also promoted the conversion of the Visigoths from Arianism to orthodox Christianity. His best-known work was Etymologies, an encyclopedia that became a standard reference work in the Middle Ages. He also wrote theological works, biographies, and treatises on natural science, cosmology, and history. He was canonized in 1598 and declared a Doctor of the Church in 1722.