ci ▁re bel led ▁again ▁in ▁al liance ▁with ▁the ▁Ga ul ish ▁tribes ▁to ▁their ▁south ▁and ▁west , ▁the ▁Tre ver i ▁and ▁N er vi i . ▁Also ▁concerning ▁these ▁powerful ▁tribes ▁it ▁is ▁difficult ▁to ▁be ▁certain ▁what ▁language ▁they ▁spoke , ▁although ▁the ▁Tre ver i ▁are ▁generally ▁thought ▁to ▁have ▁spoken ▁a ▁C elt ic ▁language . ▁( T ac it us ▁says ▁of ▁these ▁two ▁tribes ▁that ▁they ▁were ▁not ▁originally ▁Germ ani , ▁but ▁that ▁they ▁wished ▁to ▁be ▁associated ▁with ▁that ▁name ▁and ▁not ▁the ▁so fter ▁name ▁of ▁the ▁Ga uls .) ▁ ▁The ▁capital ▁of ▁the ▁E bur ones ▁is ▁named ▁by ▁Ca esar ▁as ▁A du atu ca , ▁and ▁the ▁capital ▁of ▁the ▁region ▁in ▁later ▁Roman ▁times ▁was ▁A du atu ca ▁Tun gr orum ▁( mod ern ▁T ong eren ). ▁It ▁is ▁possible ▁that ▁these ▁were ▁the ▁same ▁place , ▁except ▁that ▁the ▁term ▁" A du atu ca " ▁may ▁simply ▁mean ▁" fort ification ". ▁One ▁reason ▁for ▁doubt ▁is ▁that ▁Ca esar ▁seems ▁to ▁indicate ▁that ▁A du atu ca ▁was ▁near ▁the ▁centre ▁of ▁the ▁E bur one ▁territory , ▁and ▁that ▁the ▁main ▁part ▁of ▁this ▁territory ▁lay ▁between ▁the ▁Me use ▁( D utch ▁Ma as ) ▁and ▁the ▁Rh ine , ▁while ▁Belg ian ▁Lim burg ▁lies ▁entirely ▁to ▁the ▁west ▁of ▁the ▁Ma as . ▁ ▁A part ▁from ▁the ▁E bur ones , ▁the ▁A du atu ci