In the West, but not in the East, the laity were mostly illiterate for many centuries, and this gave the Church an advantage in the West which it did not possess in the East. The prestige of Rome surpassed that of any Eastern city, for it combined the imperial tradition with legends of the martyrdom of Peter and Paul, and of Peter as first Pope. The Emperor’s prestige might have sufficed to cope with that of the Pope, but no Western monarch’s could. … For all these reasons, the emancipation of the Pope from Byzantine domination was essential both to the independence of the Church in relation to secular monarchs, and to the ultimate establishment of the papal monarchy in the government of the Western Church.

Bertrand Russell, History of Western Philosop…, loc. 1520