"The Song of the Crusade against the Albigensian Quetzals" is a literary work written in medieval Europe by Guillaume de Tudel and Guillaume Agnellier. The book tells about the events of the crusade against the Albigensian heretics in the 12th century, unfolding before the reader a complex picture of religious conflicts and political intrigues of that time. The authors skillfully combine historical facts with legends and romantic events, which makes this work interesting both for fans of history and for lovers of adventure literature. Shades of morality, faith, the discovery of true knowledge and the eternal struggle between good and evil - all this is reflected in the "Song of the Crusade against the Albigensian Kets".