text: The Council of Chalcedon was a church council held from 8 October to 1 November , 451 AD , at Chalcedon ( a city of Bithynia in Asia Minor ) , on the Asian side of the Bosporus .
simplified: The Council of Chalcedon was an ecumenical council that took place from October 8 to November 1 , 451 , at Chalcedon ( a city of Bithynia in Asia Minor ) .