Gui de Cavalhon, Cavaillo, or Gavaillo was a Provençal nobleman: a diplomat, warrior, and man of letters. He was probably also the Guionet who composed tensos and partimens with Cadenet, Raimbaut de V
Louis VIII of France taking Marmande, from the sole surviving manuscript of the Song of the Albigensian Crusade. Recent studies have proposed Gui de Cavalhon as the author of the second part of the Song.