New discoveries uncover how the Romans ruled the seas for four centuries. Archeologists dive a small cargo ship wrecked off Sukosan, Croatia, from the 1st Century CE; test two replica small river patrol boats in Gunzenhausen, Germany, from the 2nd and 4th Centuries CE; and explore the Roman harbor at Puteoli, Italy, the largest transit port for Rome at the beginning of the 1st Century CE. 

Archaeologists are excavating the vast frontier of the Roman Empire, investigating the battle to keep it safe at Vindolanda along Hadrian's Wall in northern England, Carnuntum in Austria along the River Danube, and Gunzenhausen in southern Germany.