The Lateran Treaty marked a significant moment in the relationship between the Italian state and the Vatican. Following the Italian unification in the 19th century, the Papal States were annexed by Italy, leading to tensions and political strife between the Catholic Church and the Italian government. The treaty was negotiated against the backdrop of Mussolini's fascist regime, which sought to consolidate power and gain legitimacy by securing the support of the Church. The agreement, signed on February 11, established Vatican City as an independent state, addressing the Church's temporal sovereignty. It also included provisions for church-state relations, such as the recognition of Roman Catholicism as the state religion of Italy and the provision of financial compensation to the Vatican for the loss of the Papal States.

The treaty's signing was a crucial diplomatic maneuver. It not only alleviated decades of tension but also strengthened the relationship between the Fascist regime and the Catholic Church. Following the signing, the Church gained influence over Italian politics, and Mussolini's government was able to secure a significant base of support among the Catholic populace. The Lateran Treaty remains a fundamental document in shaping the legal and diplomatic foundation of the Vatican's interaction with Italy and the world.