The classical sources put the blame of starting the Second Celtiberian War on the city of Segeda (near Zaragoza). Appian wrote that the war broke out because this powerful city of the Celtiberian tribe of the Belli persuaded the people of some smaller towns to settle there and was building a circuit of walls seven kilometres long. It also forced the neighbouring Titti to join in. The Belli had agreed to the treaties Tiberius Sempronius Gracchus had made with tribes in Hispania at the end of the First Celtiberian War. Rome considered that Segeda was breaking the treaty. It forbade the building of the wall, demanded the tribute and the provision of a contingent for the Roman army in accordance with the stipulations of Gracchus' treaty. The Segedans replied that the treaty forbade the construction of new towns, but did not forbid the fortification of existing ones. They also said that they had been subsequently released from the tribute and the military contingent by the Romans. This was true, but the senate argued that when it granted such exemptions it always specified that they were to continue only during its pleasure.