The Pope, which word signifies Father, or Patriarch, of Rome, had from the Apostolic times been always elected, like all other bishops, by the general consent of the flock, both clergy and people; and, after the conversion of Constantine, the Emperor, as first lay member of the Church, of course had a powerful voice in the election, could reject any person of whom he disapproved, or nominate one whom he desired to see chosen, though still subject to the approval of clergy and people.
This power was, however, seldom exercised by the emperors at Rome, after the seat of empire had been transferred to Constantinople, and their power over Italy was diminishing through their own weakness and the German conquests. The election continued in the hands of the Romans, and in general, at this time, their choice was well-bestowed; the popes were, many of them, saintly men, and, by their wisdom and authority, often guarded Rome from the devastations with which it was threatened by the many barbarous nations who invaded Italy. So it continued until Pope Zaccaria quarrelled with Astolfo, King of Lombardy, and summoned the Carlovingian princes from France to protect him. These Italian wars resulted in Charles-le-Magne taking for himself the crown of Lombardy, and in his being chosen Roman Emperor of the West, by the citizens of Rome, under the influence of the Pope; while he, on his side, conferred on the pope temporal powers such as none of his predecessors had enjoyed.
From thenceforth the theory was, that the Pope was head of the Western Church, with archbishops, bishops, clergy, and laity, in regular gradations under him; while the Emperor was in like manner head of the State, kings, counts, barons, and peasants, in different orders below him; the Church ruling the souls, the State the bodies of men, and the two chieftains working hand in hand, each bearing a mission from above; the Emperor, as a layman, owning himself inferior to the Pope, yet the Pope acknowledging the temporal power of the crowned monarch.
This was a grand theory, but it fell grievously short in the practice. The city of Rome, with its worn-out civilization, was a most corrupt place; and now that the Papacy conferred the highest dignity and influence, it began to be sought by very different men, and by very different means, from those that had heretofore prevailed. Bribery and every atrocious influence swayed the elections, and the wickedness of some of the popes is almost incredible. At last the emperors interfered to check the dreadful crimes and profanity at Rome, and thus the nomination of the Pope fell absolutely into their hands, and was taken from the Romans, to whom it belonged.