Robert was born in Stockport, the second son of millwright, John Thompson and his wife Mary. As well as his older brother, Frank, he had a younger sister called Ada. The family lived at 43 Oxford Street and, later, at 12 Love Lane. Before he enlisted into the army, Robert had worked as a clerk at Johnson's - a firm of solicitors with offices on Vernon Street. He joined up on 18 March 1916, going overseas after training on 18 July. A month later, he was dead.
The Battle of the Somme had started on 1 July and, in the southern part of the battlefield, there had been almost constant fighting around High Wood, with parts of the Wood regularly changing hands. By the middle of August, it was still divided territory, with the Germans firmly in control of the northern half whilst the British had made slight inroads from the south. During the night of 18/19 August, the Fusiliers moved back into the front line here, taking over from the Argyll and Sutherland Highlanders. The Regimental History records "It was a most unpleasant tour of duty. The wood and its approaches had changed greatly, and from open warfare had become the scene of trench warfare, reeking of the dead. It was continually shelled. The Battalion bombed the enemy line but failed to move him; he, in his turn, crawled forward on two occasions and bombed ours, but equally failed to make any impression - he was jumpy and nervous. The Battalion was relieved by the 1st Cameronians on the 22nd."
By then, Robert was dead, killed by either the enemy shelling or their grenade (bomb) attacks. His body was never recovered and identified. The lieutenant commanding his platoon wrote to his mother "I very much regret to have to inform you that your son, Private Robert Thompson, No. 39173, was killed on the night of 20 - 21st of August. He was engaged on some work for which he had personally volunteered. We shall miss him very much. He was getting on splendidly. I have been out here myself over a year and I can honestly say that I have met very few men who settled down so quickly and who seemed so quickly to understand just what was wanted. He was to me a very valuable member of the platoon and I cannot say how sorry I am to lose him. It may be some comfort to you to know that he was killed instantly. I regret that I have been so long in writing to you but for the last eight days we have had a busy hard time and this is my first opportunity of writing my letters. Perhaps one or two of his friends may write to you but please let me say how sorry we all feel for you, for we had all learnt to like your son."