«Beau Sabreur - Complete Adventures of Major De Beaujolais» by P.C. Wren

Beau Sabreur focuses on the adventures of Major Henri De Beaujolais, an officer in the French Foreign legion, known as the "Beau Sabreur", title given to him by his uncle, General de Beaujolais. When Henri and his legionary friends, Raoul de Redon and Dufour do not return in time to leave Algiers they end up in jail. The general sends Henry into the desert to learn the local customs with a mission to conclude the signing of a crucial peace treaty, during which he meets Mary Vanbrugh, an American journalist. A traitor, Becque attacks them… The novel provides a detailed and fairly authentic description of life in the pre-1914 Foreign Legion, which has led to suggestions that P. C. Wren himself served with the legion.

Percival Christopher Wren (1875 - 1941) was an English writer, mostly of adventure fiction. He is remembered best for Beau Geste, a much-filmed book of 1924, involving the French Foreign Legion in North Africa. This was one of 33 novels and short story collections that he wrote, mostly dealing with colonial soldiering in Africa. While his fictional accounts of life in the pre-1914 Foreign Legion are highly romanticized, his details of Legion uniforms, training, equipment and barrack room layout are generally accurate, which has led to unproven suggestions that Wren himself served with the legion.