The gospel account has Jesus take the role of the household slave at the last supper and wash his disciples' feet, and Peter object to it, which is the point of the story. The rite is kept on Maundy Thursday — maundy from mandatum, the new commandment given in the same passage. Popes had washed the feet of twelve priests in a basilica for centuries. Francis moved it to prisons, hospitals and refugee centres from 2013 and included women and Muslims, and the liturgical rubric, which had specified men, was formally amended in 2016 to allow anyone. Anabaptist and Mennonite congregations never treated it as annual pageantry — some keep it as a regular ordinance alongside communion, which is closer to what the text describes. It is the clearest ritual statement in the tradition that authority is supposed to invert, and the fact that it needed a papal intervention to stop being clergy-only says something about how well that holds.