The generous policy of Tib. Sempronius Gracchus in B.C. 179 had secured for Spain a long period of tranquillity. But in B.C. 153, the inhabitants of Segeda having commenced rebuilding the walls of their town, which was forbidden by one of the articles in the treaty of Gracchus, a new war broke out, which lasted for many years. The Celtiberians in general espoused the cause of Segeda, and the Consul Q. Fabius Nobilior made an unsuccessful campaign against them. His successor, the Consul M. Claudius Marcellus, grandson of the Marcellus who was celebrated in the Second Punic War, carried on the war with vigor, and concluded a peace with the enemy on very fair terms (B.C. 152). The Consul of the following year, L. Lucinius Lucullus, finding the Celtiberians at peace, turned his arms against the Vaccæi, Cantabri, and other nations as yet unknown to the Romans. At the same time the Prætor Ser. Sulpicius Galba invaded Lusitania, but, though he met with some advantage at first, he was subsequently defeated with great loss, and escaped with only a few horsemen. In the following year (B.C. 150) he again invaded the country from the south, while Lucullus attacked it from the north. The Lusitanians therefore sent embassadors to Galba to make their submission. He received them with kindness, lamented the poverty of their country, and promised to assign them more fertile lands, if they would meet him in three bodies, with their wives and children, in three places which he fixed upon. The simple people believed him. But he meditated one of the most atrocious acts of treachery and cruelty recorded in history. He fell upon each body separately, and butchered them, men, women, and children, without distinction. Among the very few who escaped was Viriathus, the future avenger of his nation. Galba was brought to trial on his return to Rome on account of this outrage; and Cato, then in the 85th year of his age, inveighed against his treachery and baseness. But Galba was eloquent and wealthy, and the liberal employment of his money, together with the compassion excited by his weeping children and ward, obtained his acquittal.
Viriathus appears to have been one of those able guerrilla chiefs whom Spain has produced at every period of her history. He is said to have been first a shepherd and afterward a robber, but he soon acquired unbounded influence over the minds of his countrymen. After the massacre of Galba, those Lusitanians who had not left their homes rose as a man against the rule of such treacherous tyrants. Viriathus at first avoided all battles in the plains, and waged an incessant predatory warfare in the mountains; and he met with such continued good fortune, that numbers flocked to his standard. The aspect of affairs seemed at length so threatening that in B.C. 145 the Romans determined to send the Consul Q. Fabius Maximus into the country. In the following year Fabius defeated Viriathus with great loss; but this success was more than counterbalanced by the revolt of the Celtiberians, the bravest and most noble-minded of the Spaniards. The war is usually known by the name of the Numantine, from Numantia, a town on the River Douro, and the capital of the Arevaci, the most powerful of the Celtiberian tribes.
Henceforward two Roman armies were employed in Spain, one in the north against the Celtiberians, and the other in the south against Viriathus and the Lusitanians. The war against the Lusitanians was at first brought to a conclusion. In B.C. 141 Viriathus surprised the Proconsul Fabius Servilianus in a narrow pass, where escape was impossible. He used his victory with moderation, and suffered the Romans to depart uninjured, on condition of their allowing the Lusitanians to retain undisturbed possession of their own territory, and recognizing him as a friend and ally of Rome. This treaty was ratified by the Roman people; but the Consul Q. Servilius Cæpio, who succeeded Fabius in the command in southern Spain, found some pretext for violating the peace, and renewed the war against Viriathus. The latter sent envoys to Cæpio to propose fresh terms of peace; but the Roman Consul persuaded them, by promises of large rewards, to murder their general. On their return they assassinated him in his own tent, and made their escape to the Roman camp before the Lusitanians were aware of the death of their chief. But, when the murderers claimed their reward, the Consul coolly told them that the Romans did not approve of the murder of a general by his own soldiers. The Lusitanians continued in arms a little longer, but the war virtually terminated by the death of Viriathus. Their country was finally reduced to subjection by the Consul D. Junius Brutus in B.C. 138, who also crossed the rivers Douro and Minho, and received the surname of Callaïcus in consequence of his receiving the submission of the Callaïci, or Gallæci, a people in the northwest of Spain.
The war against the Celtiberians was at first conducted with success by the Consul Q. Metellus Macedonicus, who during his Prætorship had defeated the pretender to the Macedonian throne. But the successors of Metellus experienced repeated disasters, and at length, in B.C. 137, the Consul C. Hostilius Mancinus, being entirely surrounded by the Celtiberians, was obliged to sign a peace with them, in which he recognized their independence. He only obtained these terms on condition that his Quæstor, Tib. Sempronius Gracchus, who was greatly respected by the Spaniards for his father's sake, should become responsible for the execution of the treaty. The Senate refused to ratify it, and went through the hypocritical ceremony of delivering over Mancinus, bound and naked, to the enemy. But the Numantines, like the Samnites in a similar case, declined to accept the offering.
The Numantine war continued in the same disastrous manner to the Roman arms, and the people now called upon Scipio Africanus to bring it to a conclusion. We have already traced the career of this eminent man till the fall of Carthage. In B.C. 142 he was Censor with L. Mummius. In the administration of the duties of his office he followed in the footsteps of Cato, and attempted to repress the growing luxury and immorality of his contemporaries; but his efforts were thwarted by his colleague. He vainly wished to check in the people the appetite for foreign conquests; and in the solemn prayer which he offered at the conclusion of the lustrum he changed the usual supplication for the enlargement of the Republic into one for its preservation. He was now elected Consul a second time, and was sent into Spain in B.C. 134. His first efforts were directed, as in Africa, to the restoration of discipline in the army, which had become disorganized and demoralized by every kind of indulgence. Two remarkable men served under Scipio in this war. Marius, afterward seven times Consul, and the Numidian prince Jugurtha. Having brought his troops into an effective condition, Scipio, in the following year, proceeded to lay siege to Numantia. The town was defended by its inhabitants with the courage and perseverance which has pre-eminently distinguished the Spaniards in all ages in the defense of their walled towns. It was not till they had suffered the most dreadful extremities of famine, eating even the bodies of the dead, that they surrendered the place (B.C. 133). Fifty of the principal inhabitants were selected to adorn Scipio's triumph; the rest were sold as slaves, and the town was leveled to the ground. He now received the surname of Numantinus, in addition to that of Africanus.
During the Numantine war Rome was menaced by a new danger, which revealed one of the plague-spots in the Republic. We have already had occasion to describe the decay of the free population in Italy, and the great increase in the number of slaves from the foreign conquests of the state. As slaves were cheap, in consequence of the abundant supply, the masters did not care for their lives, and treated them with great barbarity. A great part of the land in Italy was turned into sheep-walks. The slaves were made responsible for the sheep committed to their care, and were left to supply themselves with food as they best could. It was an aggravation of their wretched lot, that almost all these slaves had once been freemen, and were not distinguished from their masters by any outward sign, like the negroes in the United States. In Sicily the free population had diminished even more than in Italy; and it was in this island that the first Servile War broke out. Damophilus, a wealthy landowner of Enna, had treated his slaves with excessive barbarity. They entered into a conspiracy against their cruel master, and consulted a Syrian slave of the name of Eunus, who belonged to another master. This Eunus pretended to the gift of prophecy, and appeared to breathe flames of fire from his mouth. He not only promised them success, but joined in the enterprise himself. Having assembled to the number of about 400 men, they suddenly attacked Enna, and, being joined by their fellow-citizens within the town, quickly made themselves masters of it. Great excesses were committed, and almost all the freemen were put to death with horrid tortures. Eunus had, while yet a slave, prophesied that he should become king. He now assumed the royal diadem, and the title of King Antiochus. Sicily was at this time swarming with slaves, a great proportion of them Syrians, who flocked to the standard of their countryman and fellow-bondsman. The revolt now became general, and the island was delivered over to the murderous fury of men maddened by oppression, cruelty, and insult. The Prætors, who first led armies against them, were totally defeated; and in B.C. 134 it was thought necessary to send the Consul C. Fulvius Flaccus to subdue the insurrection. But neither he, nor the Consul of the following year, succeeded in this object; and it was not till B.C. 132 that the Consul P. Rupilius brought the war to an end by the capture of Tauromenium and Enna, the two strong-holds of the insurgents. The life of Eunus was spared, probably with the intention of carrying him to Rome, but he died in prison at Morgantia.
About the same time died Attalus Philometor, the last king of Pergamus, leaving no children (B.C. 133). He beqeuathed his kingdom and treasures to the Roman people; but Aristonicus, a natural son of Eumenes, the father of Attalus, laid claim to the crown. He even defeated the Consul P. Licinius Crassus, who fell in the engagement (B.C. 131), but he was himself defeated and taken prisoner in the following year. The kingdom of Pergamus was formed into a Roman province under the name of Asia (B.C. 129).
The foreign dominions of Rome now comprised the ten following provinces, to which is added the date of the formation of each: 1. Sicily, B.C. 241. 2. Sardinia and Corsica, B.C. 238. 3, 4. The two Spains, Citerior and Ulterior, B.C. 205. 5. Gallia Cisalpina, B.C. 191. 6. Macedonia, B.C. 146. 7. Illyricum, probably formed at the same time as Macedonia. 8. Achaia, that is, Southern Greece, virtually a province after the capture of Corinth, B.C. 146, though the exact date of its formation is unknown. 9. Africa, consisting of the dominions of Carthage, B.C. 146. 10. Asia, including the kingdom of Pergamus, B.C. 129. To these an eleventh was added in B.C. 118 by the conquest of the southern portion of Transalpine Gaul between the Alps and the Pyrenees. In contrast with the other portions of Gaul, it was frequently called simply the "Provincia," a name which has been retained in the modern Provence.