The Romans started to conquer the Iberian Penninsula in 218 a.d., after they managed to overpower the different groups which inhabited the Aragonese terrritory, such as the Ilergetes, Celts, Sedetanos, Iberians, and Basques, etc. Some of these groups put up tremendous resistance, for example the Ilergetes, who fought for as long as twenty years. But by the beginning of the first Century almost all the territory was dominated by Rome.

In the beginning the Roman domination was military, exploiting the economic resourses that they found, but in time the inhabitants began to be like Romans themselves.

The Roman Emperor Augusto, continued the work begun by Cesar and founded the settlement called Caesaragusta in 24 a.d. Also, he set up an administrative organization, reformed the jurisprudence, and even modernized the economy by establishing a commonly used currency, which was the Roman denario.

Amongst the Romans there were exellent architects, and craftspeople who knew how to work with clay or stone, etc. The economy was based on agriculture, with the cultivation of cereals, vines, olives or fruit trees which were then transformed into bread, oil and wine.

In this way, by the middle of the first Century, Caesaraugusta became the main operative centre for Rome in Aragón, finishing the Roman colonization of all the territory in such a way that the inhabitants of Caesaraugusta (Zaragoza) were considered citizens of Rome, just like the inhabitants of Bilbilis(Calatayud), Osca(Huesca) and Turiaso (Tarazona), although their official language which was Latin took a long time to be commonly used.

The end of the Roman domination in Aragón finally came with the Germanic invasion.