▁the ▁region ▁had ▁to ▁a ▁large ▁extent ▁arrived ▁during ▁the ▁Bron ze ▁and ▁Iron ▁A ges . ▁The ▁E bur ones ▁who ▁were ▁in ▁this ▁area ▁when ▁Ca esar ▁conquer ed ▁it , ▁are ▁associated ▁by ▁arch ae olog ists ▁with ▁a ▁material ▁culture ▁which ▁has ▁its ▁roots ▁in ▁local ▁variations ▁of ▁the ▁Ur n field ▁culture . ▁It ▁is ▁during ▁the ▁late ▁Iron ▁Age ▁that ▁there ▁is ▁arch ae ological ▁evidence ▁for ▁the ▁development ▁of ▁a ▁" C elt ic ▁field " ▁system ▁in ▁the ▁less ▁fert ile ▁Camp ine , ▁and ▁increasing ly ▁social ▁strat ification ▁and ▁central ization , ▁even ▁though ▁the ▁area ▁remained ▁relatively ▁un - develop ed ▁compared ▁to ▁other ▁nearby ▁parts ▁of ▁Europe . ▁ ▁Comp ared ▁to ▁surrounding ▁areas ▁of ▁Europe , ▁one ▁remarkable ▁thing ▁about ▁this ▁pre - R oman ▁period ▁is ▁the ▁lack ▁of ▁hill ▁for ts , ▁a ▁pattern ▁throughout ▁all ▁of ▁Fland ers . ▁Only ▁one ▁is ▁known ▁in ▁Lim burg , ▁at ▁C aster ▁or ▁Cast a ert ▁in ▁R iem st , ▁right ▁in ▁the ▁sout he astern ▁corner ▁of ▁Lim burg . ▁In ▁the ▁rest ▁of ▁Fland ers ▁only ▁one ▁more ▁is ▁known , ▁at ▁As se . ▁ ▁The ▁" G erm ani " ▁and ▁the ▁" Bel ga e " ▁ ▁The ▁only ▁surv iving ▁written ▁source ▁of ▁information ▁which ▁is ▁specifically ▁about ▁Belg ian ▁Lim burg ▁before ▁it ▁became ▁part ▁of ▁the ▁Roman ▁emp ire ▁is ▁Julius ▁Ca esar , ▁who ▁left ▁a ▁famous ▁Comment ary