1952 Belgium

Issued in 1952 as a semi-postal stamp to coincide with the 13th Congress of the Universal Postal Union held in Brussels, this 40-franc plus 10-franc stamp is one of the most beautifully engraved Belgian stamps of the postwar era. The design depicts the Château de Beaulieu at Machelen, a 17th-century Belgian country house built in 1654, shown in a richly detailed oval vignette framed with baroque scrollwork and surmounted by an eagle. The château's heraldic arms appear below the building, and the dates and inscription "Castellum Beaulieu Machelen 1654" complete the design. The surcharge of 10 francs above the 40-franc postal rate went to benefit charitable causes associated with the congress.

The Universal Postal Union was established in 1874 as the General Postal Union and adopted its current name in 1878. Before its founding, every pair of countries that exchanged international mail had to negotiate separate postal treaties with one another — a cumbersome system that made international correspondence slow, expensive, and unpredictable. The UPU brought uniformity and simplicity to worldwide postal exchange, and its congresses, held every few years in member countries, set the rules governing international mail for the following period. The 1952 Brussels Congress was a particularly significant meeting — it formally recognized the UPU's relationship with the newly established United Nations system, and introduced simultaneous interpretation in French, English, Russian, and Spanish for the first time in UPU Congress history.