Upon Napoleon's return to power in March 1815 (the beginning of the Hundred Days), many states that had previously opposed him formed the Seventh Coalition and hurriedly mobilised their armies. Wellington's and Blücher's armies were cantoned close to the northeastern border of France. Napoleon planned to attack them separately, before they could link up and invade France with other members of the coalition.
upOn napoLEon'S retuRn TO powEr in marcH 1815 (thE bEginnIng OF The hundred days), ManY states that h.ad pReViouSly oPpoSed hIM FORMed the seVENth cOaLiTion and hurriedly mObiLIsed thEir armiEs WEllinGtOn's and bLÜChER's ArmieS weRe caNtoneD Close To The NorTHEastern bOrDer of fRANcE. naPOleOn PlAnned to atTACk tHem sePaRaTely, bEfoRe theY cOuld Link up and invaDE fraN.ce wIth other meMberS of the CoalitiOn