Blackburn was promoted to lieutenant. In early March, he was hospitalised for two weeks with neurasthenia. The battalion sailed for France in late March, arriving in early April. By this time, Blackburn was posted to a platoon in D Company. Western Front Blackburn went on leave in France from 29 April to 7 May. The 10th Battalion entered the fighting on the Western Front in June, initially in the quiet Armentières sector of the front line. While in this area, Blackburn was selected as a member of a special raiding party led by Captain Bill McCann. In the early hours of 23 July, the 10th Battalion was committed to its first significant action on the Western Front during the Battle of Pozières, part of the Battle of the Somme. Initially, A Company under McCann were sent forward to assist the 9th Battalion, which was involved in a bomb (hand grenade) fight over the O.G.1 trench system. Held up by heavy machine gun fire and bombs, McCann, who had been wounded in the head, reported to the commanding officer (CO) of the 9th Battalion, Lieutenant Colonel James Robertson, that more help was needed. About 05:30, a detachment of 50 men based on 16 Platoon, D Company, 10th Battalion, was then sent forward under Blackburn to drive the Germans out of a section of trench. Blackburn, finding that A Company had suffered heavy casualties, immediately led his men in rushing a barricade across the trench. Breaking it down, and using bombs, they pushed the Germans back. Beyond this point, preceding artillery bombardments had almost obliterated the trench, and forward movement was exposed to heavy machine gun fire. Blackburn, along with a group of four men, crawled forward to establish the source of the German machine gun fire, but all four of the men were killed, so he returned to his detachment. He went back to Robertson, who arranged support from trench mortars. Under the cover of this fire, Blackburn again went forward with some of his men, but another four were killed by machine gun fire. Another report to Robertson resulted in artillery support, and Blackburn was able to push forward another before being held up again, this time by German bombers. Under cover from friendly bombers, Blackburn and a sergeant crawled forward to reconnoitre, establishing that the Germans were holding a trench that ran at right angles to the one they