Historical Events in Church Annals for October 8:
The Fourth Ecumenical Council convenes in Chalcedon in which Monophysitism was condemned. The Council was convened by the great Pope Saint Leo I on this day and lasted until November 1, 451 with 17 sessions with nearly 600 bishops attending, tripling the amount who attended the previous Ecumenical Council at Ephesus twenty years earlier.
The Ministry of San Marcos (Saint Mark's) in Venice is established.
The remains of the Apostle and Evangelist Saint Mark are moved from Alexandria to the Dicastry of Venice and the new tomb of Saint Mark at St. Mark's Ministery where it exists today.