The year 206 BC marked a turning point when Roman forces defeated Carthaginians at the Battle of Ilipa. This victory allowed Rome to seize control of southern Iberian territories previously held by their enemies. Two new provinces emerged from this conquest: Hispania Citerior along the eastern coast and Hispania Ulterior in the south. These regions roughly corresponded to modern autonomous communities like Aragon, Catalonia, Valencia, and Andalusia.
Celtiberian tribes soon found themselves sharing borders with these newly established Roman provinces. Hostilities erupted almost immediately as local groups resisted Roman presence. In 197 BC, twenty thousand Celtiberians attacked a Roman army near Iliturgis. Five years later, ten thousand Celtiberians joined forces with the Turduli against Rome. A consular army led by Cato the Elder was dispatched to quell the unrest.
Despite failing to capture Saguntia, Cato managed to halt hostilities in 195 BC through diplomatic pressure. His successor, Marco Fulvio Nobilior, achieved a decisive victory over a coalition of Celtiberians, Vaccei, and Vettones near Toletum in 193 BC. Another clash occurred in 185 BC where a Hispanic coalition defeated two praetorian armies before being crushed near the Tagus river.
Quintus Fulvius Flaccus intensified operations in 182 BC by conquering Urbicua. The Celtiberians responded by raising an army of thirty-five thousand men. This force represented one of their largest military mobilizations ever recorded. Flaccus received reinforcements including three thousand Roman infantry, six thousand allied infantry, and five hundred cavalry units.
First Celtiberian Conflict
The siege of Aebura in 181 BC became a defining moment when Flaccus engaged the massive Celtiberian army near Talavera de la Reina. Twenty-three thousand Celtiberians died during this engagement while four thousand seven hundred were captured. Roman losses remained minimal at only two hundred soldiers plus eight hundred allies and two thousand four hundred native auxiliaries.
Flaccus then marched across Carpetania to Contrebia, most likely located at Fosos de Bayona in Cuenca. Heavy rains delayed a defending Celtiberian army that arrived too late to save the city. When Romans emerged from the surrendered gates, they caught fleeing defenders off guard. Twelve thousand men perished while five thousand prisoners, four hundred horses, and sixty-two banners fell into Roman hands.
A third campaign began after Flaccus learned his successor Tiberius Sempronius Gracchus was delayed. He ravaged distant parts of Celtiberia where the Lusones tribe resided along the River Iberus. During his return journey to Tarraco, Flaccus faced an ambush at the Manlian Pass. Though he killed seventeen thousand enemies and captured three thousand seven hundred men, he lost four thousand four hundred of his own troops.
Gracchus took command in 179 BC and negotiated treaties with multiple tribes including the powerful Thurru. He imposed the vicensima tax requiring five percent grain harvest contributions. This system proved more efficient than previous methods involving private tax farmers. Gracchus founded colonies like Gracchurris in Alfaro and Iliturgi as mining towns and frontier outposts.