Sanctuary Ring c.1200 showing decorative hatching.
In 511 AD, at the Council of Orleans, sanctuary was granted to anyone who took refuge in a church - thieves, adulterers or even murderers. If the suspect could reach the church (it was not necessary to enter, touching a sanctuary ring was sufficient) they were then able to seek the protection of the church authorities. They would have to make a full confession and then were given time to choose between two options: to stand trial, or to admit their guilt publicly and go into exile. Anyone who returned could be executed by the law and/or excommunicated by the Church.
The system was abolished by James I in 1623.