[3][4][5][6] When the Second World War broke out Campbell was 45 years old and a major commanding a battery in the 4th Regiment Royal Horse Artillery in Egypt.

When Italy declared war in June 1940, Campbell, by then a lieutenant colonel, was commanding the artillery component of 7th Armoured Division's Support Group under Brigadier William Gott.

The British Army was heavily outnumbered by the Italians, so General Archibald Wavell formulated a plan with his senior commanders to retain the initiative by harassing the enemy using mobile all-arms flying columns.

[5] During Operation Compass Campbell's guns played an important role in 7th Support Group's involvement in the decisive battle at Beda Fomm in February 1941 which led to the surrender of the Italian Tenth Army.

Brigadier Campbell's small force, holding important ground, was repeatedly attacked and wherever the fighting was hardest he was to be seen either on foot, in his open car or astride a tank.

According to Alan Moorehead, He led his tanks into action riding in an open armoured car, and as he stood there, hanging on to its windscreen, a huge well-built man with the English officer's stiff good looks, he shouted, 'There they come, let them have it.'

He purportedly received a letter of congratulation from General Johann von Ravenstein, commander of the 21st Panzer Division, one of the armoured formations which Campbell had faced at Sidi Rezegh.

When interviewed later as a prisoner of war, Ravenstein freely expressed his "greatest admiration" for Campbell's skill on "those hot days" and recalled "all the many iron that flew near the aerodrome around our ears".

Standing in his car with a blue flag, this officer personally formed up tanks under close and intense fire from all natures of enemy weapons.

On the following day the enemy attacks were intensified and again Brigadier Campbell was always in the forefront of the heaviest fighting, encouraging his troops, staging counter-attacks with his remaining tanks and personally controlling the fire of his guns.

In spite of his wound he refused to be evacuated and remained with his command, where his outstanding bravery and consistent determination had a marked effect in maintaining the splendid fighting spirit of those under him.A memorial to Campbell stands in his old school, Sedbergh, commemorating his brave deeds.