Brigadier Ralph Alger Bagnold, OBE,[1] FRS,[2] (3 April 1896 – 28 May 1990) was an English 20th-century desert explorer, geologist and soldier.

[4][5][6][7][8] He returned to the forces in the Second World War, in which he founded the behind-the-lines reconnaissance, espionage and raiding unit the "Long Range Desert Group", serving as its first commanding officer in the North Africa campaign.

[10] After the war Bagnold studied engineering at Gonville and Caius College, Cambridge, obtaining an MA before returning to active duty with the British Army in 1920 with the Royal Corps of Signals.

In 1932 Bagnold explored the Mourdi Depression, in present-day Chad, and found implements dated to the Palaeolithic period in the valley.

Many of the dunes fell away sharply at the far side and if you arrived at the top at full speed, you were likely to plunge headlong over the precipice.

[13] Bagnold wrote, "Never in our peacetime travels had we imagined that war could ever reach the enormous empty solitudes of the inner desert, walled off by sheer distance, lack of water, and impassable seas of sand dunes.

"[citation needed] On 10 June 1940 Italy declared war on the United Kingdom in alliance with Germany while Bagnold was in Cairo due to an accident involving a troopship collision that he was on interrupting his journey elsewhere.

Upon hearing the news and realizing that North Africa was about to become a theatre of war, he requested an interview with General Archibald Wavell, Commander-in-Chief Middle East.

Wavell granted Bagnold authority to form a unit along these lines, with it being constituted in July 1940 with the name Long Range Desert Group (L.R.D.G.).

In October 1941 he was promoted to the post of Deputy Signal Officer-in-Chief Middle East, with the temporary rank of Brigadier and worked on camouflage and deception operations.

[14][15] On 7 June 1944 Bagnold retired from the British Army with the end of military operations in North Africa after the Axis powers' defeat in that theatre.

[2] After the war Bagnold continued to work in the field of the geological science, and he published academic papers into his nineties.