CELTIBERIA, a term used by Greek and Roman writers to denote, sometimes the whole north-east of Spain, and sometimes the north-east part of the central plateau of the peninsula. The latter was probably the correct use. The Celtiberi, in this narrower sense, were not so much one tribe as a group of cantons—Arevaci, Pelendones, Berones and four or five others. They were the most warlike people in Spain, and for a long time offered a stubborn resistance to the Romans. Originally Carthaginian mercenaries, they were induced to serve the Romans in a similar capacity, and Livy (xxiv. 49) distinctly states that they were the first mercenaries in the Roman army. They did not, however, keep faith, and several campaigns were undertaken against them. In 179 b.c. the whole country was subdued by T. Sempronius Gracchus, who by his generous treatment of the vanquished gained their esteem and affection. In 153 they again revolted, and were not finally overcome until the capture of Numantia (133). The twenty years’ war waged round this city, and its siege and destruction by Scipio the Younger (133 b.c.) form only the most famous episode in the long struggle, which has left its mark in entrenchments near Numantia excavated in 1906-1907 by German archaeologists. After the fall of Numantia, and still more after the death of Sertorius (72 b.c.), the Celtiberians became gradually romanized, and town life grew up among their valleys; Clunia, for instance, became a Roman municipality, and ruins of its walls, gates and theatre testify to its civilization; while Bilbilis (Bambola), another municipality, was the birthplace of the eminently Roman poet Martial. The Celtiberians may have been so called because they were thought to be the descendants of Celtic immigrants from Gaul into Iberia (Spain), or because they were regarded (cf. Lucan iv. 9) as a mixed race of Celts and Spaniards (Iberians); in either case the name represents a geographer’s theory rather than an ascertained fact. That a strong Celtic element existed in Spain is proved both by numerous traditions and by the more trustworthy evidence of place-names. The Celtic place-names of Spain, however, are not confined to Celtiberia or even to the north and east; they occur even in the south and west.
A long description of the manners and customs of the Celtiberi is given by Diodorus Siculus (v. 33, 34). Their country was rough and unfruitful as a whole (barley, however, was cultivated), being chiefly used for the pasture of sheep. Its inhabitants either led a nomadic life or occupied small villages; large towns were few. Their infantry and cavalry were both excellent. In battle, they adopted the wedge-shaped formation of the column. They carried double-edged swords and short daggers for use hand to hand, the steel of which was hardened by being buried underground; their defensive armour was a light Gallic shield or a round wicker buckler, and greaves of felt round their legs. They wore brazen helmets with purple crests, and rough-haired black cloaks, in which they slept on the bare ground. Like the Cantabri, they washed themselves with urine instead of water. They were said to offer sacrifice to a nameless god (Strabo iii. p. 164) at the time of the full moon when all the household danced together before the doors of the houses. Although cruel to their enemies, they were hospitable to strangers. They ate meat of all kinds, and drank a kind of mead. E. Hübner’s article in Pauly-Wissowa’s Realencyclopadie, iii. (1886-1893), collects all the ancient references, which are almost all brief. Strabo’s notice (bk. iii.), based perhaps on Poseidonius, is fullest.