MERCADIER (d. 1200), French warrior of the 12th century, and chief of freebooters in the service of Richard I. of England. In 1183 he operated for Richard, then duke of Aquitaine, in the Limousin and the Angoumois, taking castles and laying waste the country. We know nothing of him during the ten years 1184-1194, but after Richard's return from Palestine, Mercadier accompanied him everywhere, travelling and fighting by his side. Richard eulogized Mercadier's exploits in his letters, and gave him the estates left by Ademar de Bainac, who died without heirs about 1190. During the various wars between Richard and Philip Augustus of France, Mercadier fought successively in Berry, Normandy, Flanders and Brittany. When Richard was mortally wounded at the siege of Chalus in March 1199, Mercadier avenged him by hanging the defenders of the chateau and flaying the crossbowman who had shot the king. Mercadier then entered the service of John, and ravaged Gascony. On Easter Monday, the loth of April 1200, he was assassinated while on a visit to Bordeaux to pay his respects to Eleanor of Aquitaine, who was bringing from Spain Blanche of Castile. His murderer was an agent of Brandin, another freebooter in the service of John. See Geraud, Mercadier, in BibHotheque de 1'Ecole des Chartes, 1st series, t. iii., pp. 417-443.