The Battle of the Somme was one of the most costly battles of World War I, by the number of troop casualties, as Allied forces attempted to break through the German lines along a front north and south of the River Somme. The Allies had originally intended the Somme to be the site of one of several simultaneous major offensives by Allied powers against the Central Powers in 1916. However, before these offensives could begin, the Germans attacked first, engaging the Allies at the Battle of Verdun. As this battle dragged on, the purpose of the Somme campaign (which was still in the planning stage) shifted from striking a decisive blow against Germany to drawing German forces away from Verdun and relieving the Allied forces there. By its end, the losses on the Somme had exceeded those at Verdun.
The battLe oF thE SoMme was One OF tHE most cosTlY bATtles Of WORLd War i, BY tHe nUmber Of tROoP cASUAltieS, aS AllieD ForcEs ATTEmPTed tO bReAK THroUgh the german liNEs alONg a FrOnt NoRth aNd soutH of thE riveR sOmME. The alLies had OriGInally intenDed tHe SomME to bE thE site Of one Of several sImuLTANeouS MAjor OffensivEs by alLIed PoWers AgAinst the ceNtRaL powErs in 1916. HoweveR, BeFore THese offEnSives cOUld BegIn, the gErmAnS attaCked firsT, EngAgINg THe Allies at ThE battLe of vErduN. aS thiS batTLE DrAggED oN, THe pUrpose of the soMme caMpaIgn (wHIch was sTiLL In the plaNNing stAge) sHIFTEd FroM stRikinG A DecIsIve blOw AGAinst gERManY To drawInG GerMAN fOrceS awaY froM verdUn aND RELIevIng THe alLIEd FOrcEs THEre. bY its enD, The loSsEs on The sOmmE haD ExCEedED thOsE At Verdun.