The Principality of Serbia or Serbian Principality is an early medieval state of the Serbs ruled by the Vlastimirović dynasty, that exists from ca 768 to 969 in Southeastern Europe.

It is established through a unification of several provincial chiefs under the supreme rule of a certain Višeslav, the first known Serbian ruler by name (fl.

768–814).

In 822, the Serbs are said to rule the "greater part of Dalmatia", and at the same time the Bulgars have taken the lands to the east, preparing to conquer Serbia.

Vlastimir of Serbia defeats the Bulgar army in a three-year-war (839–842), and the two powers live in peace for some decades.

Vlastimir's three sons succeed in ruling Serbia together, although not for long; Serbia becomes a key part in the power struggle between the Byzantines and Bulgars (in predominantly Byzantine alliance), which also results in major dynastic civil wars for a period of three decades.

Serbia is annexed by the Bulgars for three years (924–927), until the return of the political hostage Prince Časlav, who unites several provinces, becoming the most powerful of the Vlastimirović.

An important event is the establishment of Christianity as state-religion in 869, and the founding of the first Serbian eparchy, the Eparchy of Ras.

The information of the Vlastimirović dynasty ends with De Administrando Imperio (fl.

950–960).

Serbia is annexed by the Byzantines in 969 and ruled as the Catepanate of Ras.