ing ▁the ▁end ▁of ▁the ▁Great ▁Ret re at ▁of ▁the ▁western ▁fl ank ▁of ▁the ▁Franco - B rit ish ▁arm ies . ▁ ▁By ▁ 4 ▁September ▁the ▁First ▁and ▁Second ▁Arm ies ▁had ▁slow ed ▁the ▁advance ▁of ▁the ▁ 7 th ▁and ▁ 6 th ▁arm ies ▁west ▁of ▁St . ▁Di é ▁and ▁east ▁of ▁Nancy , ▁from ▁where ▁the ▁Second ▁Army ▁had ▁with dra wn ▁its ▁left ▁fl ank , ▁to ▁face ▁north ▁between ▁Nancy ▁and ▁Toul . ▁A ▁gap ▁between ▁the ▁left ▁of ▁the ▁Second ▁Army ▁and ▁the ▁right ▁of ▁the ▁Third ▁Army ▁at ▁Verd un , ▁which ▁faced ▁north - west , ▁on ▁a ▁line ▁towards ▁Rev igny ▁against ▁the ▁ 5 th ▁Army ▁advance , ▁west ▁of ▁the ▁Me use ▁between ▁Var ennes ▁and ▁St . ▁M éné h ould . ▁The ▁Four th ▁Army ▁had ▁with dra wn ▁to ▁Ser ma ize , ▁west ▁to ▁the ▁Mar ne ▁at ▁Vit ry - le - Fran çois ▁and ▁then ▁across ▁the ▁river ▁to ▁Som p ons , ▁against ▁the ▁ 4 th ▁Army , ▁which ▁had ▁advanced ▁from ▁R eth el , ▁to ▁S ui pp es ▁and ▁the ▁west ▁of ▁Ch â l ons . ▁The ▁new ▁N inth ▁Army ▁held ▁a ▁line ▁from ▁Mail ly ▁against ▁the ▁ 3 rd ▁Army , ▁which ▁had ▁advanced ▁from ▁Mé zi ères , ▁over ▁the ▁V es le ▁and ▁the ▁Mar ne ▁west ▁of ▁Ch â l ons . ▁The ▁ 2 nd ▁Army ▁had