Such uniformity in the sphere of religion was impossible unless he had the support of the Papacy.

Only by a bargain with Rome could he gain the support of a solid ecclesiastical phalanx.

Finally, by erecting a French national Church, he would not only have perpetuated schism at home, but would have disqualified himself for acting the part of Charlemagne over central and southern Europe.

To re-fashion Europe in a cosmopolitan mould he needed a clerical police that was more than merely French.

To achieve those grander designs the successor of Caesar would need the aid of the successor of Peter; and this aid would be granted only to the restorer of Roman Catholicism in France, never to the perpetuator of schism.
These would seem to be the chief reasons why he braved public opinion in Paris and clung to the Roman connection, bringing forward his plan of a Gallican Church only as a threatening move against the clerical flank.