War College. He held this position until 1911, the year in which he was appointed Général de Division. Foch influenced General Joseph Joffre (Chief of General Staff, 28 July 1911 – 12 December 1916) when he drafted the French plan of campaign (Plan XVII) in 1913. In 1913 he took command of XX Corps at Nancy, and he had held this appointment for exactly one year when he led XX Corps into battle in August 1914. Military thought Foch was later acclaimed as "the most original military thinker of his generation". He became known for his critical analyses of the Franco-Prussian and Napoleonic campaigns and of their relevance to military operations in the new twentieth century. His re-examination of France's defeat in 1870 was among the first of its kind. At the college, Foch was a professor of military history, strategy, and general tactics while becoming the French theorist on offensive strategies. During his time as an instructor, Foch created renewed interest in French military history, inspired confidence in a new class of French officers, and brought about "the intellectual and moral regeneration of the French Army". His thinking on military doctrine was shaped by the Clausewitzian philosophy, then uncommon in France, that "the will to conquer is the first condition of victory." Collections of his lectures, which reintroduced the concept of the offensive to French military theory, were published in the volumes "Des Principes de la Guerre" ("On the Principles of War") in 1903, and "De la Conduite de la Guerre" ("On the Conduct of War") in 1904. While Foch advised "qualification and discernment" in military strategy and cautioned that "recklessness in attack could lead to prohibitive losses and ultimate failure", his concepts, distorted and misunderstood by contemporaries, became associated with the extreme offensive doctrines (l' offensive à outrance) of his successors. The cult of the offensive came to dominate military circles, and Foch's reputation was damaged when his books were cited in the development of the disastrous offensive that brought France close to ruin in August 1914. Foch was seen as a master of the Napoleonic school of military thought, but he was the only one of the Military College Commandants (Maillard, Langlois, Bonnal) still serving. Their doctrines had been challenged, not only by the German school, but also since about 1911 by a new French school inspired by General Loiseau de Grandmaison, which criticised them as lacking