Issued by Vatican City in 1959, this commemorative set marks the 30th anniversary of the Lateran Treaty (1929–1959), the historic agreement that established Vatican City as an independent sovereign state. The stamps feature a dignified portrait of Pope Pius XI, the pontiff who signed the treaty with Italy. The clean engraved design and bold frame emphasize the solemn importance of the event in modern Church and Vatican history. Denominations shown include 30 lire (brown) and 100 lire (blue). These stamps are valued by collectors of Vatican issues, church history, and diplomatic milestones.