Life in Argyruntum came to a standstill in the early 4th century AD. The era of peace was interrupted by attacks of barbaric nations that eventually led to the decline of the Roman state. In an attempt to bring the Adriatic coast back to Empire, East Roman Emperor Justinian built a system of fortifications to secure navigation and protect the local population. The ruins of forts and towers above Modrič and near Sveta Trojica not far from Tribanj are parts of this defensive system that briefly postponed the final decline of the ancient world in the Adriatic.