In the mid-nineteenth century a unification movement swept across Italy one of its aims was the annexation of the Papal States. One of the1400 Irish men that answered the Vatican’s call to arms was Patrick Clooney from Waterford.
In early September 1860 forces of the kingdoms of Piedmont-Sardinia crossed into the Papal States. After a brief skirmish in Perugia the Vatican forces surrendered all except one company led by Clooney. Despite being cornered in a abandoned house and vastly outnumbered the Irish refused to surrender. Due to the volume of fire the Irish retreated upstairs and only when their opponents prepared to burn the house did the Irish eventually surrender.
After the surrender the Irish were disgusted to find out that the rest of the international volunteers had surrendered already and the city had fallen. Only eighteen days after the start of the brief war the remaining Papal forces capitulated.
The international effort to defend the Vatican was doomed to failure. The relief effort was hampered by poor organisation and lack of support. However one group which distinguished themselves were the volunteers from Ireland .
Further reading I.Kenneally Courage and Conflict & R.Doyle The Popes Irish Battalion.