Signed letter signed with autograph compliments (2 lines) to Maréchal Niel. St-Cloud, November 22, 1867. 6 pp. on 2 double sheet in-4, crowned number “N” stamped in the corner, golden edges. Secret document addressed to the Minister of War. Extraordinary letter from Louis-Napoleon III Bonaparte to his Minister of War, on the organization of the French Army, based on the experience of the last wars of the Empire (Crimea and Mexico); taken under the dictation by Pietri, his private secretary, it is a rare document in which reveals all the military thought of the Emperor who poses as a real reformer by wanting to review the tactics of the army and personally confident his feelings on the subject. This document also shows the concerns of Louis-Napoléon III before the rise of Prussia and his army, three years before the War of 1870.