What do we call the medieval practice of going barefoot or fasting to show devotion?

The story behind the answer

In medieval Christianity, acts like fasting, walking barefoot, wearing hairshirts, or making pilgrimages were prescribed as “satisfaction” after confession—outward signs of contrition meant to repair the temporal effects of sin. This sacramental practice tied spiritual repentance to concrete deeds, thought to aid the soul and reduce time in purgatory.

It shaped public life: rulers performed dramatic public acts (think Henry IV at Canossa in 1077), and the Fourth Lateran Council (1215) mandated annual confession. Movements like the Flagellants during the Black Death took such acts to extremes. By contrast, asceticism is a broader lifestyle of disciplined renunciation (typical of monks), mortification refers specifically to bodily self-denial (like self-flagellation), and austerity is general strictness or frugality, not necessarily tied to sin or the sacrament.