Issued by Vatican City in 1953, this 12 Lire stamp commemorates the proclamation of the Marian Year by Pope Pius XII. The design features a dignified right-profile portrait of the Pope, alongside a Latin inscription marking the official decree of December 8, 1953. The bold Marian monogram “M” highlights the central theme of devotion to the Virgin Mary. Designed by E. Pizzi and printed by the Vatican’s State Printing Office, it stands as an important religious issue in mid-20th-century Vatican philately. Collectors value this stamp for its deep teal engraving, strong theological symbolism, and papal historical context.