The city takes its name from the river Jiu, which runs through it. In antiquity, there was a Dacian village in around the location of today's city surrounded by forests. After the Roman conquests of Oltenia (101-102), military units were stationed around the roads that connected different important routes at the time. During the digging of the Târgu Jiu - Rovinari railroad, mosaics, coins, ceramics and Roman bricks were found in the south-eastern part of the city. This and ancient testimonies support the idea that Târgu Jiu was a commercial town (a "vicus") while under the Roman Empire's rule. A very important route that connects the Danube to Transylvania runs through the city, so historians believe that part of the Roman army under Trajan's leadership stayed and then passed in the actual location of the city.