Thomas de Vio Cajetan was a bishop, cardinal, and theologian. What I found interesting about him is that he was put in charge of Luther’s hearing at Augsburg in 1518. This event lasted three days, and Rome had given clear instructions for Cajetan – no backing down.
Cajetan informed Luther on the first day of the hearing that he must recant immediately. Two days later, Cajetan concluded the reformer was a heretic and called Luther an animal. Luther’s response? He characterized Cajetan as a man no more fit to handle his case than a donkey was fit to play a harp.