The Council of Chalcedon was an important church assembly held in 451 AD in Chalcedon, near modern-day Istanbul, Turkey. It aimed to address disputes about the nature of Christ, particularly the relationship between his divine and human natures. The council produced the Chalcedonian Definition, which affirmed that Christ is both fully divine and fully human, two natures united in one person. This council was significant in shaping Christian doctrine and was attended by bishops from various regions. The decisions made at Chalcedon influenced the development of Christian theology and led to further divisions, particularly with groups that rejected its conclusions, such as the Oriental Orthodox Churches.