He was born on 21 April 1915 and was 25 years old, and a lance-corporal in the 3rd Battalion, Grenadier Guards, British Army during the Second World War when the following deed took place during the Battle of France for which he was awarded the VC.

On 21 May 1940 near the River Escaut, in the village of Esquelmes north of Tournai for 6 km in Belgium, Lance-Corporal Nicholls, although suffering from shrapnel wounds in his arm, continued to lead his section in a counter-attack against overwhelming opposition.

The announcement and accompanying citation for the decoration was published in supplement to the London Gazette on 31 July 1940, reading[1][2] 'War Office, 31st July, 1940 The KING has been graciously pleased to approve the award of the VICTORIA CROSS to:— Lance Corporal Harry Nicholls, 1st Bn, Grenadier Guards On the 21st May 1940, Lance Corporal Nicholls was commanding a section in the right-forward platoon of his company when the company was ordered to counter-attack.

At the very start of the advance he was wounded in the arm by shrapnel, but continued to lead his section forward; as the company came over a small ridge, the enemy opened heavy machine-gun fire at close range.

Lance-Corporal Nicholls then went on up to a higher piece of ground and engaged the German infantry massed behind, causing many casualties, and continuing to fire until he had no more ammunition left.