Philip Schaff,
Ante-Nicene Fathers Vol. VIII, The Decretals…
(1885)
“ From this time to Adrian I. many Bishops of Rome vied with those of Constantinople to augment their honour and power. The establishment of the Western Empire (a.d. 800) made their ambitious claims acceptable to the Latins; and they became primates of all Christendom in Western estimation, with extra-canonical and indefinite claims as “successors of St. Peter.” ”
