Principality of Romania proclaimed the Kingdom of Romania

Background. From 1859 to 1877, Romania evolved from a personal union of two principalities, Moldavia and Wallachia, known as the "Little Union," into an autonomous principality with a Hohenzollern monarchy. In May 1877, Romania was proclaimed an independent and sovereign nation, and the defeat of the Ottoman Empire in the 1877–1878 Russo-Turkish War secured that independence. After the war, Romania was forced to cede southern Bessarabia in exchange for Northern Dobruja. In this context, the country's status was raised to a kingdom in 1881.

Legal Proclamation. On 15 March 1881, the Romanian parliament amended the constitution to proclaim Romania a kingdom. This legislative act asserted full sovereignty and raised the country to the status of a kingdom. The amendment served as the legal basis for the transformation of the state from a principality to a monarchy.

Royal Transition. Carol I, born Karl Eitel Friedrich Zephyrinus Ludwig von Hohenzollern-Sigmaringen, had ruled as Prince (Domnitor) from 1866. One passage dates the kingdom's existence from 25 March [O.S. 13 March] 1881 with his crowning as King Carol I, while another states he was proclaimed King on 26 March [O.S. 14 March] 1881. He was crowned king on 10 May 1881, beginning the Romanian royal family.