After five months of familiarisation with trench warfare, 33rd Division saw its first fullscale operations during the Somme Offensive as part of XV Corps. It began to move south by train on 10 July and was in Corps Reserve during the Battle of Albert (12–13 July) before being committed to action during the Battle of Bazentin Ridge. XV Corps had taken most of its objectives on 14 July, but High Wood and Delville Wood remained in enemy hands. Next day, 19th Brigade remained in reserve while the rest of 33rd Division assaulted Switch Trench. This attack was a failure, the infantry returning to their starting positions. On the morning of 16 July 19th Bde relieved 100th Bde, and at dawn on 20 July it renewed the attack. 5th/6th Scottish Rifles were drawn up alongside 1st Cameronians just outside the British wire and attacked High Wood, preceded by a line of scouts and supported by Royal Engineers and divisional Pioneers. The attack began satisfactorily, prisoners being taken, but German machine gun nests inflicted serious casualties and the advance was held up. The brigade commander threw in his remaining troops and by the end of the day 19th Bde held the rest of the wood in its front. The Switch Line beyond was not finally captured until 27 September, and in the meantime the casualties suffered in holding the positions in High Wood under shellfire were heavy. 33rd Division was relieved from the line in early August, returning to High Wood for a new attack on 24 August for which 19th Bde was in reserve. The division was sent for rest at the end of September.