Blaise de Lasseran-Massencôme, seigneur de Montluc (or Blaise de Montluc) (c. 1502 – 26 July 1577) was a marshal of France.
He was a member of the family de Lasseran de Massencôme de Montluc ( possibly a branch of the Montesquiou family). Despite being the eldest son of a good family, he had, like most gentlemen of Gascony. He was the elder brother of Jean de Montluc. He served first as a private archer and man-at-arms in Italy, with Bayard for his captain, fought all through the wars of King Francis I of France, and was knighted at the battle of Ceresole (1544), to which victory he had brilliantly contributed as adviser to the young Duke of Enghien.
Having apparently enjoyed no patronage, he was already middle-aged. From then on, however, his merits were recognized. His chief feat was the famous defence of Siena (1555) which he related himself. When the religious wars broke out in France, Montluc, a staunch royalist, held Guyenne for the king. Henry III made him in 1574 marshal of France, an honour which he had earned by nearly half a century of service and by numerous wounds. He died at Estillac near Agen.
Montluc's reputation was made by his Commentaires de Messire Blaise de Montluc (Bordeaux, 1592), in which he described his fifty years of service (1521–1574). This book, the "soldier's Bible" (or "breviary," according to others), as Henry IV called it, is one of many books of memoirs produced by the gentry of France at that time. It is said to have been dictated, which may account for the style.
The Commentaires are in the collection of Michaud and Poujoulat, with a standard edition in the Société de l'histoire de France, ed. by M. de Ruble (5 vols, 1865–1872). See Rüstow, Militarische Biographien, v. i. (Zürich, 1858).