Mes esperis se combat is a song composed by the fourteenth-century French composer and poet Guillaume de Machaut (c.1300-1377). It is an example of the genre known as the polyphonic ballade, a love song genre. Mes esperis se combat, being a three-part ballade, has an independent upper part, called a cantus contrapuntally written against a tenor and contratenor. It is believed to date from the middle part of Machaut's period of ballade composition (sometime between 1325 and 1335) in the latter years of his patronage by John of Luxembourg, King of Bohemia. It is catalogued by Schrade as Ballade No. 39.
Machaut was the most famous and represented composer of the fourteenth century, though he was known in his own time mostly as a poet. Writing in the style known as Ars Nova ('New Art', to distinguish it from Ars Antiqua, or 'Old Art'), Machaut is largely responsible for the establishment of the polyphonic genres known as the ballade, rondeau and virelai.