Canossa

As was observed, throughout the Roman Catholic Church, the king and the temporal princes or lay rulers dominated the clergy by their appointing the bishops and the abbots and investing them with their office. This practice, it was noticed -- a practice known as "Lay Investure" -- was attended by a great evil. In the appointment of bishops, the king would be led by political or social considerations. Or, as was observed, to replenish his depleted purse, he would sell the office to the highest...