Letter Signed, to the Marquis de Castries, discussing at length the different approaches to disciplinary matters in the infantry and the cavalry. In French. 3 pp. 8 x 6 inches, fine. Paris, 22 February 1770. Louis de Brienne de Conflans d’Armentières (1711-1774), Marshal of France. During the War of the Polish Succession he served in Italy from 1733 to 1735. On 19 September 1734, he fought at Guastalla under the maréchal de Coigny and was wounded in the neck by a musket shot. On 18 October 1734 he became a brigadier, aged only 23. He served in the Bohemian expedition during the first phase of the War of the Austrian Succession, under maréchal de Belle-Isle. He returned to France in February 1743 and was made a maréchal de camp on 20 February that year. He then joined the armée d’Alsace during its campaign in Flanders. He fought at Rocourt on 11 October 1746 and brought Louis XV news of the victory. During the Seven Years’ War he initially served in Germany under marshals de Soubise and de Contades, before being put in command of the Trois Evêchés (Metz, Toul and Verdun) in 1761. He was made a marshal of France on 2 January 1768.