The arrival of Buller's force from the south gave Lord Roberts, who returned from Pretoria on August 25, the reinforcement justifying the resumption of the eastward advance. He found the troops unfavourably placed for immediate action. Botha was posted on each side of the railway near Belfast; the junction of his right with his left, which had different fronts, forming an obtuse salient angle. The greater part of the British force was south of the line and prevented by the nature of the ground from undertaking an enveloping movement on the enemy's left. Buller had kept the cavalry to heel, and it was lying compressed between him and Pole-Carew, who was entrenched round Belfast. Lord Roberts' first act was to distribute over a wider front the conglomeration of troops, which were hampering each other's movements. French with his own cavalry, but without Buller's, was sent north of the line to face Botha's right flank and to clear Pole-Carew's left flank, while Buller worked up from the south towards the line. The movement began on August 26, and by the afternoon French, having made a wide detour, had established himself north of Belfast; thus enabling Pole-Carew to leave the town and extend his division in front of the enemy's right. Buller's movement was at first directly northwards, on account of the soft ground. His march, like that of Pole-Carew on the other flank, was across the enemy's front, but neither of them was seriously checked and the casualties were few. Buller had proposed to move eastward in the direction of Dalmanutha as soon as the ground permitted, but a cavalry reconnaissance discovered the enemy posted at Bergendal, close to the railway. The position was, in fact, the point of the obtuse angle formed by the two sections of the Boer front, one of which faced S.W. towards Buller, and the other west, towards Pole-Carew; and if it could be carried not only would Botha's line be broken, but Buller would be in a good position to deal with a retreat from either section,