In the second half of the 6th century, Slavs migrated from the Bay of Kotor to the River of Bojana and the hinterland of it as well as surround the Skadar lake. They formed the Principality of Doclea. Under the following missions of Cyril and Methodius, the population was Christianised. The Slavic tribes organised into a semi-independent dukedom of Duklja (Doclea) by the 9th century.

After facing subsequent Bulgarian domination, the people were split as the Doclean brother-archonts split the lands among each other after 900. Prince Časlav Klonimirović of the Serbian Vlastimirović dynasty extended his influence over Doclea in the 10th century. After the fall of the Serbian Realm in 960, the Docleans faced a renewed Byzantine occupation through to the 11th century. The local ruler, Jovan Vladimir Dukljanski, whose cult still remains in the Orthodox Christian tradition, was at the time struggling to ensure independence.

Stefan Vojislav started an uprising against the Byzantine domination and gained a huge victory against the army of several Byzantine strategoi in Tudjemili (Bar) in 1042, which put to an end the Byzantine influence over the Doclea. In the 1054 Great Schism, the Doclea fell on the side of the Catholic Church. Bar became a Bishopric in 1067. In 1077, Pope Gregory VII recognised Duklja as an independent state, acknowledging its King Mihailo (Michael, of the Vojislavljević dynasty founded by nobleman Stefan Vojislav) as Rex Doclea (King of Duklja). Later on Mihailo sent his troops, led by his son Bodin, in 1072 to assist the uprising of Slavs in Macedonia. In 1082, after numerous pleas the Bar Bishopric of Bar was upgraded to an Archbishopric.

The expansions of the Kings of the Vojislavljević dynasty led to the control over the other Slavic lands, including Zahumlje, Bosnia and Rascia. The might of the Doclea declined and they generally became subjected to the Grand Princes of Rascia in the 12th century. Stefan Nemanja was born in 1117 in Ribnica (today Podgorica). In 1168, as the Serbian Grand Zhupan, Stefan Nemanja took Doclea. In charters of Vranjina Monastery during the 14th century the ethnic groups which are mentioned were Albanians (Arbanas), Vlahs, Latins (Catholic citizen) and Serbs.