In 184 BC, when Philip was preparing for a new war with the Romans, Appius was sent at the head of an embassy into Macedon and Greece, to observe his movements and wrest from his grasp those cities of which he had made himself master.
During the year 184 BC, while Philip was getting ready for another conflict with Rome, Appius was sent on a diplomatic mission to Macedonia and Greece. The purpose of this envoy was to keep an eye on Philip's activities and prevent him from taking over the cities he had already secured.