Sultan Amurat II (Murad) was the sixth sultan in succession, reigning from 1421 to 1444 and from 1446 to 1451. He abdicated in favor of his son after the first period but assumed command again a few years later, when the Balkan areas he had previously subdued threatened to rise up again. Amurat II had a strong interest in science, literature, and music, and his son Mehmed II invited the Venetian artist Gentile Bellini to work in Constantinople for a time.