Maurice was born on June 5, 1869, at Bayonne as the son of General Léon Duval who commanded the 77th Infantry Regiment and Louise Marie Elisabeth Mathilde (née de Leigonye).

Duval was promoted to First Lieutenant on October 1, 1892, and began taking lessons at the Valbonne Shooting Club from 1892 to 1893 and ranked 42 out of 57 by the end of his class and was assigned to the 36th Infantry Regiment on August 1, 1894.

On April 25, 1899, he was assigned to the 142nd Infantry Regiment and was given a letter of satisfaction on July 7, 1899, by the French Minister of War, Camille Krantz for his studies conducted in 1898.

[2] Upon the French entry into World War I, Duval was made Battalion Commander while he was a Lieutenant Colonel but was seriously wounded during the First Battle of Champagne.

His citation read: Constantly in reconnaissance on the front in the most advanced trenches, rendered particularly brilliant services as deputy chief of staff of an army by a real understanding of situations, tireless activity, communicative enthusiasm and a remarkable spirit of initiative.

After the failure of the Kerensky Offensive and the Russian Civil War, the French command were expecting a violent clash with the Germans and General Pétain sought to contain it.

[4][5] After the conclusion of World War I, he became part of the management committee of the Aéro-Club de France after being introduced to it by André Michelin and R. Soreau on March 10, 1921.