The Dacians were an Indo-European population historically allocated area to the north of the lower reaches of the Danube. After clashing first with the Macedonians ( fourth century BC ) and then by the Thracians ( third century BC ), in the first century BC Dacians managed to create, under King Burebista, to a stable autonomous kingdom. After the death of the great king his kingdom fell apart; it’s followed a fluid situation, with numerous clashes with the Roman Empire which in the meantime had reached the southern borders of Dacia. The clashes reached their peak in the years 85-88 AC, when the emperor Domitian conducted a series of operations against the reign of the new king, Decebal. He who had been able not only to restore a central authority over the Dacians, but also to revive the military and economic power of the times of Burebista, so as to press from the north on the Roman province of Mesia. Although defeated, 89 Decebal managed to obtain peace terms only apparently favorable to the Romans: he was in fact permitted to rearm freely and to increase the power of his people in the next fifteen years. In 101 AC Emperor Trajan started the campaign of conquest of the area, ended in 106 with the death of King Decebal and the establishment of a new Roman province. Roman rule had, however, already completed in the third century, when the Roman Limes was brought back to the Danube. Despite the relative brevity of the direct rule of Rome, the Romanization of Dacia was deep, thanks to the intense work of colonization; ethnic and linguistic characteristics of the Dacians changed in a new anthropological complex, in the following centuries further modified by the new invasions of Goths, Slavs, Magyars.