Armand de Gontaut, baron de Biron (1524 – July 26, 1592) was a celebrated French soldier of the 16th century.
His family, one of the numerous branches of the House of Gontaut, took its title from the territory of Biron in Périgord, where on a hill between the Dropt and the Lide still stands the magnificent Château de Biron begun by the lords of Biron in the 11th century.
As a page of Queen Marguerite de Navarre, Biron attracted the notice of the marshal de Brissac, with whom he saw active service in Italy. A wound he received in his early years made him lame for life, and gave him the nickname Armand Le Boiteux (the limper). But he did not withdraw from the military career, and he held a command in Guise's regiment of light horse in 1557. A little later he became chief of a cavalry regiment, and in the French Wars of Religion he repeatedly distinguished himself.
His service to the royal cause at the Battle of Dreux, Battle of Saint-Denis, Battle of Jarnac and Battle of Moncontour was rewarded in 1569 by his appointment as a privy councillor of the king and Grand Master of Artillery. He commanded the royal forces at the siege of La Rochelle in 1572, and four years later was made a marshal of France. From 1576 to 1588 he was almost continuously employed in high command.
After the assassination of Henry III in 1589, he was among the first to support the cause of Henry of Navarre, but he was suspected of prolonging the civil wars in his own interest. He brought a part of Normandy under subjection, and dissuaded Henry from going into England. He distinguished himself in the battles of Arques and Ivry against the Catholic League. Gontaud was killed by a cannonball at the siege of Épernay on July 26, 1592.
In 1585 he was chosen a godfather for Armand-Jean du Plessis, future cardinal Richelieu.
He was a man of considerable literary attainments, and used to carry a pocketbook, in which he noted everything that appeared remarkable. Some of his letters are preserved in the Bibliothèque nationale and in the British Museum; these include a treatise on the art of war. His son, Charles de Gontaut, duc de Biron (1562–1602), also became Marshal of France in 1594. A grandson of his second son, Henry, was Charles-Armand de Gontaut, another Marshal of France.