Lupeni is the most important settlement in the West Jiu Valley. It lies on the banks of the West Jiu river, in the Petrosani Depression, at a height varying between 630 m (in the east) and 760 m. The distance from Lupeni to Petrosani is 18 km (DN66A), and to Deva (the capital of Hunedoara County) is 114 km.

Establishments in Lupeni were first documented in 1770, but recent archeological findings prove that life in this are in fact goes back to the Stone Age. As early as the Roman occupation, gold deposits in the Jiu Valley, bearing alluvia, were exploited sporadically. In the earth deposits of the river, archaeologists found a bust of the Roman god Ares (the son of the Jupiter and Juno, one of the Rome's protectors).

During the Middle Ages, the population of the Jiu Valley was far from flourishing. The native inhabitants were shepherds and lived in hamlets spread along the mountains. Some villages were centered near the river, but according to documents, the entire population of the valley merely reached 400 people.

Lupeni was founded as a consequence of the intense migration by people from the Strei Valley in Tara Hategului, drawn by the rich pastures and hay fields of the region. The settlers from Valea Lupului village are said to have founded Lupeni, while the villagers of Rau Barbat formed Barbateni.

The native inhabitants of the Jiu Valley (known as "momarlani") lived an ancient and quite rustic form of life, mostly extinct in other parts of the country. Its recent one hundred years of industrialismm had changed it drastically no doubt, however to this day, centuries-old customs and traditions are still preserved.

Mining activity began in the Southern area of Lupeni, above the present - day residential districts Vascoza III and IV, East of which lies The Elisabeta shaft pit and drift (the first mining exploitation of the town). The drift entrance is well preserved and it represents a potential tourist sight, as it marked the beginnings of mining in the region.

After 1840, as the mining exploitations began, the social landscape changed dramatically. The foreign mining companies brought Polish, Czech, Slovak, Austrian, Hungarian and Romanian miners to the Jiu Valley. The miners were brought from Baia Mare or The Apuseni Mountains.

After the industrial exploitation of the pit coal deposits was started in 1881, working colonies appeared besides the old neighborhoods. They grew steadily, keeping up with the growing mining exploitation. At the start of the last century, the building of a railroad connecting Lupeni to Petrosani (and consequently to Simeria) led to unprecedented development in the area. Within half a century, the population of the town exploded, multiplying by 10. This was an unparalleled time of thriving for Lupeni. The Sfantul Stefan, Nord, Victoria, Sud, Putul Sud mines were opened, and, simultaneously, colonies were built for the workers who were to work in the strong mining center coming to life in the Jiu Valley. Stefan, Braia, Lobstein, "Culonia Oficiantilor", "Filimon Sarbu," were the names of these colonies where the ethnically, religiously and culturally varied population made a model of tolerance and co-habitation.

The economic development and the permanent increase of population imposed changes on the city's urban aspect. The old colonies had been replaced with by residential districts, parks, commercial zones and recreation and children's area.

The industrial development of the area was severely affected by the inter-war economic depression (dramatica social conflicts between the 5th and 9th of August 1929). The economic breakdown led to the government's drastic suppression of a strike in Lupeni, resulting in the tragedy; 22 dead and 58 wounded.

Lupeni was officially pronounced to be a town in 1941, when it had 12,000 inhabitants.

Lupeni quickly become the country's most important coal producer. It had a mono - industrial development, as 80% of the population lived on mining or related industries/activities. Agriculture, which previously was the main occupation in the area, became insignificant. Economic growth, as well as the transition from the agricultural way of life to the industrial one had an important effect on the urbanization. After the country became communist, most of the buildings dating back to the Austro-Hungarian era were torn down and apartment complexes were built.

After 1990 the mines started closing, which had significant repercussions on the socio-economic situation of the city. Many miners were now unemployed, most of the town's economic agents were affected.

Coal remains, however, the main natural resource of the area. Although they have been exploited for more than 130 years, the pit coal deposits are the largest in the country.

Today, Lupeni is one of the oldest cities in the Jiu Valley, with a population of 32,827 people.

Nowadays, within the administrative territory of Lupeni, there are two mines, Lupeni and Barbateni, and the Lupeni Coal Preparation Plant, which provides for the mines needs. The town is looking for a new identity after the dominating mining industry under went a dramatic change triggered by Romania's new political and economic realities. Simultaneously with the bankruptcy of the some mine-related firms, privately owned businesses appeared in Lupeni, and are now an important presence in the town's economy. During the last few years, there have appeared businesses in tourism, the timber industry, bakery, trade etc.