While trapped in the city during the Siege of Toulouse in 1218, he wrote a mock tenso between a trebuchet (trabuquet) and a siege engine called a "cat" (cata). Senhors, l'autrier vi ses falhida, as it begins, has been interpreted as cleverly disguised obscenity, but there is no reason not to take it at face value. During the siege a trebuchet was constructed by the citizens and successfully employed to destroy the besiegers' cat, just as the trabuquet of the poem defeats the cata. The Chanson de la Croisade Albigeoise contains a description of the siege (from a Toulousain viewpoint) which echoes the tenor of Escrivan's song.