St Ninian built his church, Candida Casa, at Whithorn in Galloway in 397AD, and carried the gospel to the Picts even as far as Orkney and Shetland. Skye must have been involved in this initial evangelising process, so it is safe to assume the arrival of the first Christians sometime between 400 and 450AD. We know that Ninian visited Rome and would naturally have been greatly influenced by its doctrines. However, he received many scholarly men from Gaelic Ireland, among them Finnian of Moville, who later had as a pupil the great Columba. Thus a link was established between the British and Scoto-Irish churches. It is difficult therefore to assume that the Pictish church, an off-shoot from the British, and the Scoto-Irish church were completely separate despite the ongoing warring which went on for centuries between the two peoples. This unlikely relationship greatly facilitates our understanding of the early church in Skye and Skye's involvement in this heroic age of the Gaelic speaking people.
Ninian's church in the Orkneys and Shetland, established in the early part of the 5th century, received its first attacks from Norse pirates sometime in the 6th century, and was also attacked by Aidan, king of the Dalriadans, the aforementioned Gaels who colonised the west coast of Scotland. History suggests that Pictish survivors escaped south to the east coast of Caithness and Sutherland and to the Hebrides, but this is by no means certain. What we do know is that there was a considerable Pictish settlement in the north of Skye evidenced by the finding of three of the earliest class I Pictish stones at Clachard Tote, Dunvegan and Fiskavaig.
A further class I stone to be seen in Raasay displays a superimposed leaf type cross, a style seldom seen, but found interestingly on what is known as Peter's stone at Whithorn. This early leaf cross originated in Ireland where one or two examples can be seen, notably the Stele of Arraglen (County Kerry), and the Stele of Reasg (Dingle Peninsula). A similar stone but of class II is to be seen at Papil in Shetland. These crosses were added to the Pagan stones in Scotland to indicate the displacement of the Druid religion by its Christian successors, and provide indelible proof of the progression of Christianity from Ireland to Whithorn, and from there north through the length of Scotland. The class 1 stone in Raasay, of an earlier type than the Shetland Papil stone, suggests a movement of Ninian's missionaries by sea through the inner Hebrides to Orkney and Shetland.
In the Irish annals of Tighernac and Ulster, under the date of 668, note is made of the voyage of the sons of Gartnait with the Columban clergy of Skye to Ireland, and their return two years later. These entries frequently refer to events which can be dated to some years earlier. There are historical Pictish kings of the name Gartnait and this particular entry refers to one who is recorded as being active in battle in 649. The date 668 of the entries in the Ulster annals are thought to have been copied from similar recordings made in Iona some years earlier and now lost, referring perhaps to the yeare 664, the date of the famous Synod of Whitby, when the Roman method of calculating Easter was chosen in preference to that of the Irish. We know that there was a strong Columban contingent present there to support the defeated Bishop Colman of Lindisfarne, and that following the Synod he resigned and left for Ireland, accompanied by Columban clergy who helped him build a monastery on Inisbofin (Island of the White Cow). It is intriguing to think that his company may have included the sons of Gartnait and their followers, but of this we have no definite record.