In the Office of Readings  for today's feast of St. Leo the Great, Pope, Church Father, and Doctor of the Church,  the saint reminds us that we all are kings, and we all are priests:
"For all, regenerated in Christ, are made kings by the sign of the cross; they are consecrated priests by the oil of the Holy Spirit, so that beyond the special service of our ministry as priests, all spiritual and mature Christians know that they are a royal race and are sharers in the office of the priesthood. For what is more king-like than to find yourself ruler over your body after having surrendered your soul to God? And what is more priestly than to promise the Lord a pure conscience and to offer him in love unblemished victims on the altar of one’s heart?"
Raphael's "Repulse of Attila"  depicts the meeting in 452 between Pope Leo and Attila the Hun on the banks of the Mincio River.