1. As to the first, the Sixth Canon of the Council ordered that the ancient custom should continue in force, according to which the great mother Churches of Alexandria and Antioch possessed jurisdiction over the whole civil diocese, the one of Egypt and the other of the East, in like manner as the Church of Rome possessed a similar jurisdiction in the West. The ground upon which the Council rests this canon is much to be observed; it does not institute this jurisdiction, but orders it be continued because it was the ancient custom. Now as there had been no other Council prior to that of Nicæa, in which this power of jurisdiction over the Metropolitans in the civil dioceses of Egypt and of the East had been granted to the Bishops of Alexandria and of Antioch, the origin of this ancient custom must be referred to apostolic institution, according to St. Augustine's rule, "That which is held by the whole Church, which has not been ordered by councils, but always been kept, we are most right in believing to have been handed down by none other than apostolic authority."[115] Pope Innocent I.,[116] writing to Alexander Bishop of Antioch, about eighty years after the Council, recognises his jurisdiction over not only one province, but over the whole assemblage of provinces which made up the civil jurisdiction of the Prefect of the East, not so much on the ground of the city's civil dignity as because it had been the first See of the chief of the Apostles. St. Gregory the Great[117] repeatedly in his letters speaks of the See of the chief of the Apostles as being the See of one in three places, Rome, Alexandria, and Antioch.