The Chalcedonian Definition is a statement of faith established by the Fourth Ecumenical Council in Chalcedon in 451 AD. It defines the two natures of Jesus Christ—divine and human—asserting that they coexist in one person without confusion, change, division, or separation. This definition aimed to clarify the nature of Christ and address various theological disputes of the time. This definition is significant in Christian theology, as it helped to unify beliefs about the nature of Christ among different Christian communities. It laid the groundwork for future discussions on Christology and remains a foundational doctrine for many branches of Christianity, including Eastern Orthodoxy and Roman Catholicism.