 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.