In the mid-19th century, as the Wars of the Risorgimento raged through Italy, some 20,000 men from different walks of life and varying countries gathered at the gates of Vatican City to defend their pontiff. At the heart of this story are the Papal Zouaves, steeped in a knightly code of honor, and unflinching in battle as any modern warrior, as they offer their lives to preserve their Catholic city-state and faith.