The pretext for the declaration of war was triggered by the city of Segeda (Poyo in the Mara, Zaragoza). This city was proceeding in the year 154 BC, the remodeling of its territory, bringing together willingly or by force the residents of the surrounding, expanding its campus and building a new wall of 8 km in circumference, which caused the confrontation with Rome, as interpreted this attitude it violated the treaty Celtiberian cities Ebro valley, had signed with Graco, the BC año179
The Roman Senate sent Fulvio Nobilior a consular army against segedenses that, by failing to finish fortifying the city, fled to Numancia with their wives and children, where, according to Appian, were welcomed as allies and friends, adding that Floro Numancia so unjust was dragged into the war.
