Definition: The fourth ecumenical council of the Christian Church was held at the city of Chalcedon (currently known as Kadikoy in Turkey), from October 8 to November 1, 451. The Council of Chalcedon was convoked under Pope Leo the Great and the Emperor Marcian, and it was attended by 520 bishops or their representatives. The Council of Chalcedon was the largest and best-documented of the early councils.
The primary subject under consideration by the Council of Chalcedon was the matter of Christ's dual nature. The council decreed that Christ was both divine and human, and that any philosophy that held that he was solely human or solely divine was therefore considered a heresy. This concept was specifically expressed in the Chalcedonian Creed.
The Council of Chalcedon also reinforced canons of earlier church councils and declared Jerusalem and Constantinople to be patriarchates. In addition, the council approved the Nicene Creed.
Examples:
The seventh canon of the Council of Chalcedon forbade ecclesiastics to hold a secular office or engage in military activities.
