The Council of Chalcedon (modern Turkey) defined the orthodox Christology of the Christian church, affirming that Christ is one person in two natures, 'without confusion, without change, without division, without separation.' This formulation rejected both Nestorianism and Eutychianism and established the parameters of Christological orthodoxy for most Christian traditions. Chalcedon remains a touchstone for Christian theological identity.

Chalcedonian Christology provided the theological vocabulary for the great Christological hymns of the Eastern and Western churches, from the Trisagion to the hymns of Venantius Fortunatus. Its paradoxes of incarnation—two natures in one person—inspired the metaphysical conceits of poets like John Donne and Richard Crashaw.