St. Isidore of Seville (c. 560 – 4 April 636) was a Spanish scholar, theologian, and archbishop of Seville. He is widely regarded, in the words of 19th-century historian Montalembert, as “the last scholar of the ancient world”.
At a time of disintegration of classical culture, aristocratic violence and widespread illiteracy, Isidore was involved in the conversion of the Arian Visigothic kings to Catholicism, both assisting his brother Leander of Seville and continuing after his brother’s death. He was influential in the inner circle of Sisebut, Visigothic king of Hispania. Like Leander, he played a prominent role in the Councils of Toledo and Seville.
His fame after his death was based on his Etymologiae, an etymological encyclopedia that assembled extracts of many books from classical antiquity that would have otherwise been lost. This work also helped standardize the use of the period (full stop), comma, and colon.