The exact period when the city was built is not known.
Some say the first settlement was erected between 106-107, others say it was between 108-110.
However, due to an inscription discovered at the beginning of the 14th century in the village of Grădişte, it is known that the new town was settled in the first years after the conquest of Dacia.
The inscription reads: "On the command of the emperor Caesar Nerva Traianus Augustus, son of the divine Nerva, was settled the Dacian Colony by Decimus Terentius Scaurianus, its governor."

In Rome, the settlement of the colony was marked by the minting of a coin, by order of the Senate, dedicated to emperor Trajan.

During the reign of Hadrian the city was renamed Colonia Ulpia Traiana Augusta Dacica Sarmizegetusa.
Between 222 and 235 the colony was called a metropolis.
The name was found on a stone inscription that reads "To Gaius Arrius Quadratus, son of Gaius, acting praetor of the emperor in Colonia Ulpia Traiana Augusta Dacica Sarmizegetusa."
Gaius Arrius Antoninus bore the title legatus pro praetore, which was the official title of the governor of some imperial provinces of the Roman Empire.
The exact period when the city was built is not known. Some say the first settlement was erected between 106-107, others say it was between 108-110. However, due to an inscription discovered at the beginning of the 14th century in the village of Grădişte, it is known that the new town was settled in the first years after the conquest of Dacia. The inscription reads: "On the command of the emperor Caesar Nerva Traianus Augustus, son of the divine Nerva, was settled the Dacian Colony by Decimus Terentius Scaurianus, its governor."
In Rome, the settlement of the colony was marked by the minting of a coin, by order of the Senate, dedicated to emperor Trajan.
During the reign of Hadrian the city was renamed Colonia Ulpia Traiana Augusta Dacica Sarmizegetusa. Between 222 and 235 the colony was called a metropolis. The name was found on a stone inscription that reads "To Gaius Arrius Quadratus, son of Gaius, acting praetor of the emperor in Colonia Ulpia Traiana Augusta Dacica Sarmizegetusa." Gaius Arrius Antoninus bore the title legatus pro praetore, which was the official title of the governor of some imperial provinces of the Roman Empire.
Ulpia Traiana Sarmizegetusa