The son of a Colonel in the Royal Engineers, Ralph Alger Bagnold was born at Devonport on 3rd April 1896. His sister, Enid Algerine went on to become a writer, penning National Velvet in 1935. Educated at Malvern College he entered The Royal Military Academy, Woolwich and was commissioned into the Engineers in 1915. Serving on the Western Front from September of that year, he was mentioned in Despatches and awarded the Belgian Order of Leopold.

After the war, the Army sponsored Bagnold to take an engineering degree at Gonville and Caius College, Cambridge before he resumed his career, this time with the Royal Signals serving in Egypt and on the North West Frontier of India where he was awarded another MiD. During leave periods he explored the wild countryside becoming one of the early pioneers of using motor vehicles to explore the desert. In 1929 he explored the Egyptian desert searching for the fabled lost city of Zerzura and in 1932 explored the Mourdi Depression in modern day Chad finding stone age relics. In 1935 he wrote Libyan Sands: Travel in a Dead World which is still in print. During this time Bagnold developed a sun compass, versions of which are still used today and developed the practice of reducing tyre pressure to traverse soft sand.

Leaving the Army in 1935 to concentrate on exploration, Bagnold immediately volunteered for further service upon the outbreak of war. On 10th June 1940 Italy declared war on Britain and Bagnold was in Cairo by coincidence due to a collision involving the troopship taking him to Singapore. He immediately requested an interview with the theatre commander, General Wavell, proposing a desert scouting force able to ‘commit acts of piracy’ against the Italians. In June 1940 the Long-Range Desert Group was born with Bagnold as its first Commanding Officer. Bagnold recruited fellow desert explorers Captains Patrick Clayton, Teddy Mitford and William Shaw and they populated the unit with soldiers who were self-reliant, several of the early members being New Zealand farmers.

Using Chevrolet trucks and favouring lighter two-wheel-drive vehicles, the patrols navigated by Bagnold’s sun compass and, at night, by using theodolites to take bearings from the stars. The initial reconnaissance patrols soon gave way to nuisance raids forcing the Italians to commit ever more troops to isolated outposts. However, the operations were not always one-sided and one patrol was ambushed by their Italian equivalent with four men escaping and walking 200 miles across the desert to safety. By August 1941 the LRDG numbered 350 men and had its own air wing. Bagnold was promoted to become inspector of Desert Forces in Cairo, being awarded an OBE and another MiD in the process, and his place was taken by Guy Prendergast. It is often forgotten in the hype of publicity that the early successes of the SAS were due to LRDG patrols getting them to their target in the first place.

Bagnold remained in Egypt and was promoted Brigadier before retiring when the axis forces were finally defeated in the Middle East. After the war he continued exploring and publishing academic papers well into his nineties. He devised the Bagnold Formula for calculating sand flow and the Bagnold Dune Field on Mars is named in his honour. A fellow of the Royal Society and much decorated by various academic bodies, Brigadier Ralph Bagnold, founder of the Long-Range Desert Group, died in 1990.