Two works against the Council of Chalcedon are attributed to Timothy Aelurus. The first survives fully in Armenian and as a synopsis in a Syriac epitome; its title in Armenian is very long, so today scholars call it Against the Dyophysites or On the Unity of Christ. Timothy includes over three hundred quotations not only from authors whose views he opposed but also from works cited in support of his understanding of Christology. He also refutes the Definition of Faith promulgated by the Council of Chalcedon and Leo of Rome’s Tome to Flavian of Constantinople in this work, which was endorsed by the Definition. The second work survives in a single Syriac manuscript, which dates to before 562. It consists of four parts: (1) a section-by-section refutation of the Chalcedonian Definition, (2) a section-by-section refutation of the Tome of Leo, (3) a florilegium of quotations from the acts of Ephesus II chosen to demonstrate the bishops’ stunning change of mind at Chalcedon, and (4) a eulogy for Dioscorus of Alexandria along with an exhortation to persevere in the faith.