I have found a reference to "Moylin" being one of the inhabitants of Galway about the time of the invasion by Henry 11 (1133-1189). This predates the "City of the 13 Tribes" as Galway was later dubbed. There are claims that the origins are Viking. There was a lot of Viking activity in the region at the time. Of the 24 names that are listed as living in the area about 1160, many are Welsh or of Welsh origin. Recent claims suggest that many West of Ireland folk hail from Spain or Morrocco.