, ▁and ▁some ▁oil ▁and ▁wine , ▁the ▁des ira b ility ▁of ▁which ▁caused ▁his ▁coun tr ymen ▁to ▁in va de ▁northern ▁Italy . ▁ ▁The ▁Greek ▁historian ▁Pos id on ius ▁( c . ▁ 1 3 5 – 5 0 ▁BC ), ▁whose ▁work ▁is ▁preserved ▁only ▁in ▁fragments ▁by ▁other ▁writers , ▁offers ▁the ▁earliest ▁historical ▁record ▁of ▁the ▁Hel vet ii . ▁Pos id on ius ▁described ▁the ▁Hel vet ians ▁of ▁the ▁late ▁ 2 nd ▁century ▁BC ▁as ▁" rich ▁in ▁gold ▁but ▁peace ful ," ▁without ▁giving ▁clear ▁indic ation ▁to ▁the ▁location ▁of ▁their ▁territory . ▁His ▁reference ▁to ▁gold ▁was hing ▁in ▁rivers ▁has ▁been ▁taken ▁as ▁evidence ▁for ▁an ▁early ▁presence ▁of ▁the ▁Hel vet ii ▁in ▁the ▁Swiss ▁plate au , ▁with ▁the ▁Em me ▁as ▁being ▁one ▁of ▁the ▁gold - y ield ing ▁rivers ▁mentioned ▁by ▁Pos id on ius . ▁This ▁interpretation ▁is ▁now ▁generally ▁disc arded , ▁as ▁Pos id on ius ' ▁narr ative ▁makes ▁it ▁more ▁likely ▁that ▁the ▁country ▁some ▁of ▁the ▁Hel vet ians ▁left ▁in ▁order ▁to ▁join ▁in ▁the ▁ra ids ▁of ▁the ▁Te ut ones , ▁C imb ri , ▁and ▁Am br ones ▁was ▁in ▁fact ▁southern ▁Germany ▁and ▁not ▁Switzerland . ▁ ▁That ▁the ▁Hel vet ians ▁originally ▁lived ▁in ▁southern ▁Germany ▁is ▁confirmed ▁by ▁the ▁Alexand rian ▁ge ograph er ▁Claud ius ▁P to le ma ios ▁( c . ▁ 9 0 – 1 6