Complex sentence: Legislation limited the bishops' authority even in affairs relating to clergymen until the end of the period of the Commonwealth in 1264, but the principle of the autonomy of the Church prevailed by the middle of the 14th century.
Split into simpler sentences: Legislation limited the bishops' authority until the end of the period of the Commonwealth in 1264. The principle of the autonomy of the Church only prevailed at the middle of the 14th century.