This classic Montenegro stamp, issued in 1910, commemorates the proclamation of Montenegro as a kingdom. It features a detailed portrait of King Nicholas I (Nicholas Petrovic-Njegos), the country’s first and only monarch. The denomination is 25 para, printed in deep blue with intricate ornamental background patterns and a crown motif below the portrait. The Cyrillic inscription reads "КРАЉ ЦРНА ГОРА" (King of Montenegro). A significant historical issue, it reflects Montenegro’s brief royal era before its integration into the Kingdom of Serbs, Croats, and Slovenes in 1918. This issue remains highly collectible for Balkan and royal-themed collections.