The Requiem mass of Pierre de la Rue is easily his best known composition and has garnered more recordings than any of his other works (or any other early Requiem, for that matter). The composition is unique among his masses for various components, such as including polyphony for both proper and ordinary movements, shifting dramatically in range between different movements, and descending lower than any mass of the period. At the same time, the Requiem also shares numerous traits with other of La Rue’s works, including the use of multiple melodic models and varied treatment of its pre-existent material. Significantly, La Rue’s Requiem is highly unusual in containing quotations from two different works of mourning that argue for the creation of the mass after the death of Philip the Fair in 1506. Because of this likely terminus post quem, the Requiem will be used as a jumping off point for construction of a tentative stylistic chronology of La Rue’s chant-based masses, the most numerous of his mass types.