Nikšić (Никшић, nîkʃit͡ɕ), is the second largest city in Montenegro, with a total population of 56,970 located in the west of the country, in the centre of the spacious Nikšić field at the foot of Trebjesa Hill. It is the center of Nikšić Municipality with population of 72,443 according to 2011 census, which is the largest municipality by area and second most inhabited after Podgorica. It was also the largest municipality by area in the former Yugoslavia. It is an important industrial, cultural, and educational center.
In classical antiquity, the area of Nikšić was the site of the settlement of the Illyrian tribe of the Endirudini and was known in sources of the time as Anderba or Enderon. The Roman Empire built a military camp (castrum Anderba) in the 4th century AD, which was known as the Ostrogothic fortress Anagastum (after 459. AD). After Slavic settlement in the region, Anagastum became Slavic Onogošt, which was the name of the town and župa (county) in the Middle Ages. Onogošt was renamed as Nikšić in the middle of 15th century after the Nikšići, a Montenegrin tribe.
The region formed one of the core areas of the Illyrian kingdom with its capital in Rhizon. It was inhabited by the Endirudini, who figure in the list of tribes which surrendered to Octavian in 33 BC. The Endirudini were one of the tribes who were included in the administrative reorganization of the tribal units in the early Roman Empire and became part of the Docleatae with Doclea as their administrative center.
During the Early Middle Ages, it was located within the South Slavic (Sklavenoi) tribal provinces of Travunia or Duklja (which were under the authority of the Serbian Principality of the Vlastimirović dynasty). With the fall of the Vlastimirovići and the hinterland regions in the second half of the 10th century, Doclea was resurrected with Stefan Vojislav and his Vojislavljević dynasty, succeeded by Stefan Nemanja and his Nemanjić dynasty, at which time the Onogošt župa existed.