How did the Lateran Treaty of 1929 settle the conflict between Italy and the papacy?

The Lateran Treaty of 1929 resolved the long-standing Roman question—a dispute between the church and the Italian state that began with the unification of Italy in 1870 and the subsequent seizure of the Papal States.1

The treaty settled this conflict through a mutual recognition of sovereignty:

• Papal Recognition: The papacy formally recognized the state of Italy, with Rome as its capital.2
• State Recognition: Italy recognized the full sovereignty and independence of the pope over Vatican City, a small territory of 44 hectares.23

Beyond these territorial terms, the agreement included a concordat that addressed ecclesiastical affairs, such as the validity of Catholic marriage under canon law and the provision of religious instruction in public schools. This pact established a framework for church-state relations that was later confirmed by the Italian constitution of 1948.2