Aquileia was founded as a colony by the Romans in 180/181 BC along the Natiso River, on land south of the Julian Alps but about north of the lagoons. The colony served as a strategic frontier fortress at the north-east corner of transpadane Italy (on the far side of the Po river) and was intended to protect the Veneti, faithful allies of Rome during the invasion of Hannibal in the Second Punic War and during the Illyrian Wars. The colony would serve as a citadel to check the advance into Cisalpine Gaul of other warlike peoples, such as the hostile Carni to the northeast in what is now Carnia and Histri tribes to the southeast in what is now Istria. In fact, the site chosen for Aquileia was about 6 km from where an estimated 12,000 Celtic Taurisci nomads had attempted to settle in 183 BC. However, since the 13th century BC, the site, on the river and at the head of the Adriatic, had also been of commercial importance as the end of the Baltic amber ("sucinum") trade. It is, therefore, theoretically not unlikely that Aquileia had been a Gallic "oppidum" even before the coming of the Romans. However, few Celtic artefacts have been discovered from 500 BC to the Roman arrival.