Since enlisting into the Zouavaes during almost 2 years Alfonso Carlos was taking part in trainings, maneuvers and other peacetime service of papal army. When Italian troops assaulted Rome he served as alférez in the 6. Company of the 2. Battalion. It was deployed along Aurelian Walls and concentrated around Porta Pia, on key axis of Italian assault. The fighting took place on September 20, 1870. For a few hours and heavily outnumbered, the Zouaves resisted onslaught of the bersaglieri shock units; some authors refer to the “famous last stand”. The papal order to give up was not accepted unanimously and some detachments kept fighting until all units surrendered later that day. Alfonso was neither recognized nor revealed his identity and for 3 days with other POWs he was kept imprisoned; they were then shipped to Toulon and released. He transferred to Graz and got married the following year.