The first of these periods began while the Carthaginians were still in the peninsula, and lasted for upwards of seventy years. This was an era of bitter and often temporarily successful resistance to Rome,--a matter which taxed the resources of the Roman Republic heavily. The very lack of union of the Spanish peoples tended to prolong the conflict, since any tribe might make war, then peace, and war again, with the result that no conquests, aside from those in the east and south, were ever secure. The type of warfare was also difficult for the Roman legionaries to cope with, for the Spaniards fought in small groups, taking advantage of their knowledge of the country to cut off detachments or to surprise larger forces when they were not in the best position to fight. These military methods, employed by Spaniards many times in their history, have been given, very appropriately, a Spanish name,--_guerrilla_ (little war). Service in Spain came to be the most dreaded of all by the Roman troops, and several times Roman soldiers refused to go to the peninsula, or to fight when they got there, all of which encouraged the Spanish tribes to continue the revolt. The Romans employed harsh methods against those who resisted them, levelling their city walls and towers, selling prisoners of war into slavery, and imposing heavy taxes on conquered towns. They often displayed an almost inhuman brutality and treachery, which probably harmed their cause rather than helped it. Two incidents stand out as the most important in this period, and they illustrate the way in which the Romans conducted the war,--the wars of the Romans against the Lusitanians and against the city of Numantia in the middle years of the second century B.C. [Sidenote: Viriatus.] The Roman leader Galba had been defeated by the Lusitanians, whereupon he resorted to an unworthy stratagem to reduce them. He granted them a favorable peace, and then when they were returning to their homes unprepared for an attack he fell upon them, and mercilessly put them to death. He could not kill them all, however, and a determined few gathered about a shepherd named Viriatus to renew the war. Viriatus was a man of exceptional military talent, and he was able to reconquer a great part of western and central Spain. For eight or nine years he hurled back army after army sent against him, until at length the Roman general Servilianus recognized the independence of the lands in the control of Viriatus. The Roman government disavowed the act of Servilianus, and sent out another general, Cæpio by name, who procured the assassination of Viriatus. Thereafter, the Lusitanians were unable to maintain an effective resistance, and they were obliged to take up their abode in lands where they could be more easily controlled should they again attempt a revolt. [Sidenote: The wars of Numantia.]