Expecting a long war in Hispania, the Senate decided in 153 BC for the first time that the election of the magistrates would take place on 1 January, instead of 15 March. This allowed "Quintus Fabius Nobilitor" to arrive in Hispania and start his campaign early in the year. The people of Segeda, whose wall had not been completed, fled and sought refuge among the Arevaci of Numantia (7 km north of Soria), who welcomed them. The Arevaci initially tried to mediate, but Nobilitor would only accept complete surrender ("deditio"). Consequently, the Celtiberians raised an army of 20,000 infantry and 500 cavalry, and chose a Segedan, Carus, as its commander. He prepared for an ambush in a thick forest and attacked the nearly 30,000-strong Roman army of Nobilitor. It was a long battle, which the Celtiberians won; 6,000 Romans were killed. Carus was killed together with 6,000 of his men by the Roman cavalry which was guarding the Roman baggage while he was pursuing the fugitives from the battle in a disorderly manner. Nevertheless, the battle was a disaster for the Romans and from then on they would not engage in battle on the day of the festival of the god Vulcan because this defeat occurred on that day.