In 154 BC, the Roman Senate objected to the Belli town of Segeda building a circuit of walls, and declared war.
The next consul, Lucius Licinius Lucullus, attacked the Vaccaei, a tribe living in the central Duero valley which was not at war with Rome.
After the war, they established two Roman provinces: Hispania Citerior (Nearer Spain) along most of the east coast, an area roughly corresponding to the modern autonomous communities of Aragon, Catalonia and Valencia, and Hispania Ulterior (Further Spain) in the south, roughly corresponding to modern Andalusia.
A consular army by Cato the Elder was sent to the Celtiberia, and, despite not being able to take Saguntia,[1] prompted the Celtiberians to stop hostilities in 195 BC.
Soon after Cato returned to Rome, in 193 BC, a coalition of Celtiberians, Vaccei and Vettones was defeated by Marco Fulvio Nobilior near Toletum.
[6] The details given by Livy suggest that the Celtiberians formed an organised coalition, using an army composed both by cavalry and infantry, and fighting in closed battle formations by using banners.
[9] Since his successor, Tiberius Sempronius Gracchus, was late, Flaccus started a third campaign against the Celtiberians who had not surrendered, ravaging the more distant parts of Celtiberia, where the Lusones lived.
The town asked for help to a Celtiberian military camp in the nearby city of Alce,[15] who sent ten envoys to enquire the Romans about the reasons of the attack.
After Gracchus ordered the entire army to march in review in front of them, the legates left and discouraged their people from sending aid to the besieged city.
Gracchus then captured the city, and negotiated the defection of some important nobles, including what Livy thought was by far the most powerful man in Hispania, a Celtiberian chief named Thurru.
[19] Livy thought that some of the surrenders were in bad faith because whenever Gracchus left hostilities resumed and there was also a major battle near Mons Chaunus (probably Moncayo Massif) with many casualties on both sides.
[21] Unlike previous praetors he spent time to negotiate and cultivate personal relations with tribal leaders.
[24] There is some evidence that he introduced civilian administrative measures, such the issuing of rights for mining to mint coins and the construction of roads.
Appian wrote that this war broke out because Segeda (near Zaragoza), a 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.
The Belli had agreed to the treaties Tiberius Sempronius Gracchus had made with tribes in Hispania at the end of the First Celtiberian War.
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.
[28] The senate must have decided to withdraw the exemptions because it was worried about the development of Segeda into a powerful city in the land of the Celtiberians, who had a history of rebellions.
[29] The Arevaci assembled at the town of Numantia (7 km north of Soria) which had strong natural defences, and chose Ambo and Leuco as their leaders.
These Roman disasters encouraged the town of Ocilis (Medinaceli, in the modern province of Soria) to defect to the Celtiberians.
[30] In 152 BC Marcus Claudius Marcellus, consul for the third time, took over the command, bringing 8,000 infantry and 500 cavalry to Hispania.
His moderation encouraged the people of Nertobriga (a town of the Belli, in the modern province of Zaragoza) to ask for peace.
Marcellus chained the horsemen, sold their horses, plundered the countryside and began to besiege the town, which sent a herald to ask for peace again.
They asked either that the Roman army should remain in Hispania and that it should be commanded by a consul to check the malpractices of the Arevaci or, if the troops were to be withdrawn, that Rome should inflict an exemplary punishment on them.
According to Polybius, when the envoys of the Arevaci were heard, they came across as not being willing to submit or to accept defeat and gave the impression that they thought that they had fought more brilliantly than the Romans.
[32] Appian wrote that the senate was not happy that these people had refused the terms put forward earlier by Nobilitor.
Then, the young Publius Cornelius Scipio Aemilianus spoke in the senate and asked to be allowed to be sent to Hispania as an officer or a junior commander and that he was ready to assume such role.
He sought to persuade the Celtiberians to put matters in his hands because he wanted to bring the war to an end before the arrival of Lucullus.
[36] Appian wrote that Lucius Licinius Lucullus was greedy for fame and money and attacked the Vaccaei because he was ‘in straitened circumstances'.
He crossed the River Tagus and encamped near the town of Cauca (Coca) The inhabitants asked him what he had come for and what the reason for war was.
The Caucaei attacked a party of Roman wood cutters and foragers, killed many of them and pursued the fugitives to their camp.