 The army was intended to carry out the breakthrough and exploitation of the Somme offensive, once the Fourth Army (General Sir Henry Rawlinson) had captured the German front-line trenches.In May it had been envisaged that Gough would stand by to take over the two right flank corps of the Fourth Army but on 5 June, this plan was supplemented by a proposal to move the forces under Gough to the Second Army in Flanders, if the Fourth Army offensive bogged down.The idea of Gough taking over the right wing corps was dropped later in June and the 1st, 3rd and 2nd Indian cavalry divisions were attached to Gough along with the 12th and 25th divisions in GHQ reserve, to operate under the command of GHQ.