Art Ó Laoghaire (O'Leary) was a Roman Catholic, one of the few surviving Catholic gentry. The anti-Catholic Penal Laws in force in Ireland during the 18th century imposed severe restrictions on most of the population in terms of education, employment, trade, ownership of property and the practice of their religion. The wealthy resorted to private tutors and clandestine property arrangements, the poor to hedge schools, and large numbers of Irish went abroad, often to serve in foreign armies. Ó Laoghaire had been educated on the Continent and served as a captain in the Hungarian Hussars, a Regiment of Empress Marie Theresa's Army of Austro-Hungary.