Original sentence: The provincial structure of the church in 1318 was much the same as it had been when it was established in 420 by the Synod of Isaac, and many of the fourteenth-century dioceses had existed, though perhaps under a different name, nine hundred years earlier
Edited sentence: The provincial structure of the church in 1318 was much the same as it had been when it was established in 420 at the synod of Isaac, and many of the fourteenth-century dioceses had existed, though perhaps under a different name, nine hundred years earlier