Though Manuel was the youngest of John's four sons he was chosen to succeed his father due to his ability to listen to advice and learn from his mistakes (or so his father discerned). He continued the Komnenian restoration admirably, particularly in the Balkans where he consolidated Byzantine holdings and inflicted a crushing defeat on the Kingdom of Hungary in 1167 at the Battle of Sirmium. With this victory the Kingdom of Hungary was made a vassal of the Empire and, according to noted Byzantine historian Paul Magdalino, Byzantine control over the Balkans was at its most effective point since Late Antiquity.