Haec regio ex descriptione Augusti nona est". This region was smaller than the original area occupied by the Ligurians in more ancient times: it was probably that in this province the purest Ligurian ethnicity was still preserved, while in nearbies Regio XI Transpadana (North of Po river) and in Provence the tribes were heavy celtised. People with Ligurian names were living south of Placentia, in Italy, as late as 102 AD. In 126 A.D. the Liguria region was the birthplace of Pertinax, Roman soldier and politician who became Roman Emperor. The area of the Alpes Cottiae province, named after Cottiust, the local king of Ligurian tribe of Segusini, who initially resisted Augustus' imperialism but eventually submitted and became the emperor's ally and personal friend. His territory, together with that of the other Alpine tribes, was annexed to the Roman empire in 15 BC - although Cottius, and his son after him, were accorded the unusual privilege of continuing to govern the region, with the title of "praefectus" i.e. Roman governor. In 8 BC, Cottius showed his gratitude for this reprieve from dynastic oblivion by erecting a triumphal arch to Augustus in his capital, "Segusio" (Susa, Piedmont, Italy), which still stands. After the death of Cottius' son, the emperor Nero (ruled 54-68) appointed a regular equestrian procurator to govern the province. Aeschylus, in a fragment of "Prometheus Unbound", represents Hercules as contending with the Ligures on the stony plains, near the mouths of the Rhone, and Herodotus speaks of Ligures inhabiting the country above Massilia (modern Marseilles, founded by the Greeks). Thucydides also speaks of the Ligures having expelled the Sicanians, an Iberian tribe, from the banks of the river Sicanus, in Iberia. The Periplus of Pseudo-Scylax describes the Ligyes (Ligures) as living along the Mediterranean coast from Antion (Antibes) as far as the mouth of the Rhone and then intermingled with the Iberians from the Rhone to Emporion in Spain. Traditional accounts suggested that the Ligures represented the northern branch of an ethno-linguistic layer older than, and very different from, the proto-Italic peoples.