Eleven tribes of South East Britain surrendered to Claudius and the Romans prepared to move further west and north. The Romans established their new capital at Camulodunum and Claudius returned to Rome to celebrate his victory. Caratacus escaped with his family, retainers, and treasure, to continue his resistance further west. After the invasion, Verica may have been restored as king of the Atrebates although by this time he would have been very elderly. In any case a new ruler for their region, Cogidubnus, soon appeared as his heir and as king of a number of territories following the first stage of the conquest as a reward as a Roman ally. AD 44–60 Vespasian took a force westwards, subduing tribes and capturing oppida settlements as he went. The force proceeded at least as far as Exeter, which became a base for the Roman legion, Legio II Augusta, from 55 until 75. Legio IX Hispana was sent north towards Lincoln () and by 47 it is likely that an area south of a line from the Humber to the Severn Estuary was under Roman control. That this line is followed by the Roman road of the Fosse Way has led many historians to debate the route's role as a convenient frontier during the early occupation. It is unlikely that the border between Roman and Iron Age Britain was fixed with modern precision during this period. Late in 47 the new governor of Britain, Publius Ostorius Scapula, began a campaign against the tribes of modern-day Wales, and the Cheshire Gap. The Silures of southeast Wales caused considerable problems to Ostorius and fiercely defended the Welsh border country. Caratacus himself led this guerilla campaign but was defeated when he finally chose to offer a decisive battle; he fled to the Roman client tribe of the Brigantes who occupied the Pennines. Their queen Cartimandua was unable or unwilling to protect him however, given her own accommodation with the Romans, and handed him over to the invaders. Ostorius died and was replaced by Aulus Didius Gallus who brought the Welsh borders under control but did not move further north or west, probably because Claudius was keen to avoid what he considered a difficult and drawn-out war for little material gain in the mountainous terrain of upland Britain. When Nero became emperor in 54, he seems to have decided to continue the invasion and appointed Quintus Veranius