Charles Jean Jacques Joseph Ardant du Picq (1819-1870) was a French Army officer and military theorist of the mid-nineteenth century whose writings, as they were later interpreted by other theorists, had a great effect on French military theory and doctrine. As a major with the 16th Chasseur Battalion, Ardant du Picq served in Syria from 1860 to 1861 during the French intervention to restore order during Maronite-Druze sectarian violence. He also saw extensive service in Algeria (1864-66) and in 1869 was appointed colonel of the 10th Line Infantry Regiment. He was in France at the outbreak of war with Prussia in 1870 and took command of his regiment, the Tenth Regiment of the Line. He published Combat Antique (Ancient Battle), which was later expanded from his manuscripts into the classic Etudes sur les Combat: Combat Antique et Moderne, often referred to by its common English title as Battle Studies: Ancient and Modern Battle. This work was published in part in 1880 posthumously, and the complete text did not appear until 1902. The difficulties surrounding reform of the French military and its organization were widely discussed and his work referenced, and it was a very popular work among the army during World War I.