Flagellants are practitioners of a form of mortification of the flesh by whipping their skin with various instruments of penance. Many Christian confraternities of penitents have flagellants, who beat themselves, both in the privacy of their dwellings and in public processions, in order to repent of sins and share in the Passion of Jesus.In the 14th century, a movement within Western Christianity known as Flagellantism became popular and adherents "began beating their flesh in a public penitential ritual in response to war, famine, plague and fear engendered by millenarianism." Though this movement withered away, the practices of public repentance and promoting peace were adopted by the flagellants in Christian, especially Roman Catholic, confraternities of penitents that exist to the present-day. History
Flagellation (from Latin flagellare, to whip) was quite a common practice amongst the more fervently religious throughout antiquity. Christianity has formed a permanent tradition surrounding the doctrine of mortification of the flesh, ranging from self-denial, wearing hairshirts and chains, fasting and self-flagellation using the discipline. Those who practice self-flagellation claim that St. Paul’s statement in the Bible ‘I chastise my body’ refers to self-inflicted bodily scourging (1 Corinthians 9:27). There are prominent Christians who have practiced self-flagellation. Martin Luther, the Protestant Reformer, self-flagellated among other ascetic practices during his early years as an Augustinian monk (although he later condemned such practices). Likewise, the Congregationalist writer Sarah Osborn also practiced self-flagellation in order "to remind her of her continued sin, depravity, and vileness in the eyes of God".
This rising is said to have been started by a peasant who saw a vision. The movement became known as the laudesi from their constant hymn singing. At its peak, a group of over 15,000 adherents gathered in Modena and marched to Rome, but the movement rapidly faded when one of its leaders was burned at the stake by order of Boniface IX. In Germany
The German and Low Countries movement, the Brothers of the Cross, is particularly well documented - they wore white robes and marched across Germany in 33.5 day campaigns (each day referred to a year of Jesuss earthly life) of penance, only stopping in any one place for no more than a day. They established their camps in fields near towns and held their rituals twice a day. The ritual began with the reading of a letter, claimed to have been delivered by an angel and justifying the Flagellants activities. Next, the followers would fall to their knees and scourge themselves, gesturing with their free hands to indicate their sin and striking themselves rhythmically to songs, known as Geisslerlieder, until blood flowed. Sometimes the blood was soaked up in rags and treated as a holy relic. Originally members were required to receive permission to join from their spouses and to prove that they could pay for their food. However, some towns began to notice that sometimes Flagellants brought plague to towns where it had not yet surfaced. Therefore, later they were denied entry. They responded with increased physical penance.