About Nicholas I of Montenegro
Nicholas I of Montenegro, also known as Nikola I Petrović-Njegoš, was the last monarch of Montenegro from 1860 to 1918, reigning as prince from 1860 to 1910 and as the country's first and only king from 1910 to 1918. His grandsons were kings Alexander I of Yugoslavia and Umberto II of Italy, among others. He gave Montenegro its first constitution in 1905 following pressure from a population eager for more freedom. After the end of the First World War, a meeting in Podgorica voted to depose Nikola and annex Montenegro to Serbia.
Biography source: Wikipedia. The profile adds birthday-specific historical context from the Celebs Birthday Today editorial database.