Duklja

Doclea or Duklja (Serbian Cyrillic: Дукља) was a medieval state with hereditary lands roughly encompassing the territories of present-day southeastern Montenegro, from Kotor on the west to the river Bojana on the east and to the sources of Zeta and Morača rivers on the north. Duklja was at first a vassal of the Eastern Roman Empire until it became a part of the Serbian Principality in the 9th century, under the Vlastimirović dynasty. After the Byzantine annexation of Serbia in the late 10th century, Duklja remained under Byzantine rule until the 1040s, when the local lord Stefan Vojislav managed to achieve independence for most of the maritime region under his rule; Duklja emerged as the most powerful polity, and became the center of the Serbian realm throughout the 11th century, ruled by the Vojislavljević dynasty.