Until “Prowess,” or private vengeance, was made illegal by Tynwald Court held at Keeill Abban in 1429, a manslayer fleeing from the relatives of the victim often took refuge in Church or on other holy ground. But he was not as secure as in many Christian countries.
‘If’, said the Deemsters (judges) and the Twenty-four (Keys) declaring the ancient law in 1422, ‘any man have done any point of Treason and taketh Sanctuary for dread of punishment, the Sanctuary shall not avail him by the Law of Man.’
Similarly, within three days of a manslayer’s entry into the holy place, the Coroner (officer of the Courts) was empowered to break sanctuary and take him out if he did not acknowledge his guilt. The prisoner was then presented with three choices – a stay of not more than three days in sanctuary – which he must then abandon and take his chance – standing trial, or banishment.
If he chose the last, the Coroner was to place him in the middle of the highway leading to the harbour of his departure. If he strayed from the way he was liable to arrest by the Coroner and lodgement for trial; and whether he kept the road or not, he stood the greatest peril from the avengers of blood.
The law therefore laid it down that if he was taken by his enemies on the excuse that he had left the road, they had to bring two witnesses in proof that they had not slain or captured him on the appointed way.
(source: Manannan’s Isle by David Craine (1955))