Why is Vatican City located within Rome?

Vatican City is located within Rome as a result of the Lateran Treaty, signed in 1929 to resolve the "Roman question"—a long-standing dispute between the papacy and the Italian state.12

Following the unification of Italy in 1870, the Italian government annexed the Papal States and established Rome as the national capital. In protest, the popes refused to recognize the new political situation and remained within the Vatican grounds as self-described "prisoners" for nearly 60 years.23

The 1929 treaty settled this conflict by formally recognizing Vatican City as an independent, sovereign state. This arrangement was established to ensure the pope’s full independence and to enable him to exercise his universal authority as the head of the Roman Catholic Church from within the historic center of his ministry.143