Gormond et Isembart (English: "Gormond and Isembart")[1] is an Old French chanson de geste from the second half of the eleventh or first half of the twelfth century.[2][3] Along with The Song of Roland and the Chanson de Guillaume, it is one of the three chansons de geste whose composition incontestably dates from before 1150;[4] it may be slightly younger than The Song of Roland and, according to one expert, may date from as early as 1068.[3] The poem tells the story of a rebellious young French lord, Isembart, who allies himself with a Saracen king, Gormond, renounces his Christianity, and battles the French king. The poem is sometimes grouped with the Geste de Doon de Mayence or "rebellious vassal cycle" of chansons de geste.[3]