HistoryData
Historical EmpireBucharest

United Principalities of Moldavia and
Wallachia

Active Reign Period
18591881AD
Calculated Duration
22 Years

The United Principalities formed the nucleus of the modern Romanian state, merging Moldavia and Wallachia under one ruler and evolving into the independent Kingdom of Romania by 1881.

Key Facts

Union formed
5 February 1859 (election of Cuza)
Formal unification as Romania
3 February 1862
Independence proclaimed
21 May 1877
Became a kingdom
22 May 1881
Suzerain power
Ottoman Empire (nominal until 1877–78)

Imperial Zenith Metrics

Capital
Bucharest
Duration
22yrs

Historical Trajectory

Phase I: Rise

On 5 February 1859, Alexandru Ioan Cuza was elected Domnitor of both Moldavia and Wallachia, forming a personal union that exploited a loophole in the Paris Convention of 1856. Although both principalities remained nominally autonomous Ottoman vassals, the dual election created a single effective government. Cuza pursued administrative unification, and by February 1862 the two principalities formally merged under the name Romania, establishing the core of a modern national state.

Phase II: Zenith

Under Cuza and his successor Carol I, the new Romanian state undertook modernizing reforms including land redistribution, secularization of monastery lands, and the introduction of a unified legal code. A new constitution in 1866 codified the country's name as Romania and granted it considerable self-governance. By 1867 Romania issued its own currency, and its institutions increasingly functioned as those of a sovereign state despite residual Ottoman suzerainty.

Phase III: Decline

In February 1866, a Liberal-led coalition forced Cuza to abdicate; the German prince Karl of Hohenzollern-Sigmaringen assumed the throne as Carol I. Romania declared full independence on 21 May 1877, recognized by the Ottoman Empire in the Treaty of San Stefano. On 22 May 1881 the constitution was amended, transforming Romania into a kingdom with Carol I as its first king, concluding the principality period entirely.

Notable Imperial Reigns

Selected rulers mapping the empire’s trajectory