Former Gurgusovac, present Knjaževac, is located on the east of Serbia, along the Serbian-Bulgarian border, at the mouth of the rivers Trgoviški and Svrljiški Timok. It is surrounded by the slopes of the mountains Stara planina, Tresibaba and Tupižnica. The municipality of Knjaževac includes three anthropogeographic areas – the areas of Timok, Zaglavak and Budžak.

The area used to be inhabited by numerous tribes: Tribals, Mezi, Thracians and Timah. It fell under the Roman rule in 29 BC and during the migration times the Avars, Huns and Slavs went this way (those who settled down here were called Timočans, and the first news of them date back to 818 AD). There is a large number of sites evidencing about the life in this region from prehistory to the present: prehistoric habitats (Baranica, Valuge, Škodrino Polje, Kadijski Krst, etc.), ancient and late ancient sites (Timacum Minus near the village of Ravna, Baranica, Gradište, Koželj etc), early Christian churches (Kalna, Štrbac, Baranica, the one near the village of Ravna etc.). As regards the medieval period there are the settlement of Koželj and the churches in the villages of Donja and Gornja Kamenica, built in the 14th and 15th century. The settlement of Gurgusovac was first mentioned in the Turkish census from 15th century. Since 1396 it had been under the Turkish rule as part of the Vidin pashalik until 1833 when, together with its surrounding, it merged with Serbia under the rule of Knez Miloš. After the Turks, the town was left with the tower of Gurgusovac as one of the first symbols of the town – it was a military fort with palisades that was later on turned into a prison - notorious prison known as "Serbian Bastille", which in the times of the Karađorđevićs served as a prison for political prisoners. By order of Knez Miloš the tower was burned down and in his honor the name of the town was changed into Knjaževac on 17 January 1859. During 1875-1877 the town was occupied by the Turks again, but for a short period of time. In 1883, after the liberation wars, unresolved political and economic situation led to the rebellion known as Timočka Buna. The immediate cause of the revolt was the seizure of arms from the national army at the order of King Milan Obrenović. The leaders of the rebellion were Aleksa Aca Stanojević, Gavra Aničić, Ljuba Božinović and others. Since 1913, during the Balkan wars, this region had frequently been attacked by Bulgaria; in 1915 it was even occupied. Serbian army and French 15th Cavalry Brigade liberated Knjaževac in October 1918. During the Second World War, the area was occupied by the Germans (1941) until the final release on 10 October 1944. After the liberation, the town started developing rapidly. Nearby mines were opened again, large industrial complexes were made instead of former small trades, thus causing large migrations from rural areas into the town.
Two rivers, numerous bridges, picnic sites and boats on the water in the downtown area, the hospital, the reading-room, the church, Grammar School, numerous small trades and cafes – these were the reason why occasional passers-by, like travel writers, adventurers and spies used to call this small town "Little Venice" or "Little Paris". Famous Le Corbusier used to enjoy in the delights of this Serbian town on his way to the East.
