Wikipedia
The name "Macaire" was first documented as an Irish Saint in the Bible. It appears to have several claims of origin. It was a male name and currently is considered a male or female name.
Macaire is a common name for a 12th-century French chanson de geste, named for one of its main characters.
Macaire and La Reine Sibille (14th century) are two versions of the story of the false accusation brought against the queen of Charlemagne, called "Blanchefleur" in Macaire and "Sibille" in the later poem. Macaire is only preserved in the Franco-Venetian Geste of Charlemagne (Bibl. St Mark MS. fr. xiii.). La Reine Sibille only exists in fragments, but the tale is given in the chronicle of Alberic Trium Fontium, a monk of the Cistercian monastery of Trois Fontanes in the diocese of Chlons, and in a prose version. Macaire is the product of the fusion of two legends: that of the unjustly repudiated wife and that of the dog who detects the murderer of his master. For the former motive see Genevieve de Brabant. The second is found in Plutarch, Script. moral., ed. Didot ii. (1186), where a dog, like Aubri's hound, stayed three days without food by the body of its master, and subsequently attacked the murderers, thus leading to their discovery. The duel between Macaire and the dog is paralleled by an interpolation by Giraldus Cambrensis in a manuscript of the Hexameron of Ambrose. Aubri's hound received the name of the "dog of Montargis," because a representation of the story was painted on a chimney-piece in the chateau of Montargis in the 15th century.
The tale was early divorced from Carolingian tradition, and Jean de la Taille, in his Discours notable des duels (Paris, 1607), places the incident under Charles V.