Like the system of Watch and Ward itself, the Mustering Cross was introduced by the Vikings. It is not clear whether it differed in any way from the Watch Cross, but, according to tradition, was a small wooden cross about 18 inches high, if possible, made of keirn (Manx: mountain ash). In February, 1793, the Manx Mercury reported that the militia guarding Castle Rushen was “summoned by the ancient mode of fixing a wooden cross over their door every night”. Rather more exactly, it went from house to house through a parish by a recognised route to summon men to take their turn on watch.

When a special emergency or danger arose, the Captain would send out a runner to call the parish to arms or to attendance. It is understood that the last muster was made in Kirk Patrick in 1843, when Captain Richard Quirk of Raby summoned parishioners to urge them to attend a Vestry Meeting to secure the appointment of a promising candidate as teacher in the parochial school. It took the runner three days to ride round the parish which had, at that time, a large population of miners.