"Scots came from Ireland"

It of course also depends on what is meant by Scots. Mostly when people think of Scots then they think of the people who inhabit Scotland and of course it is pretty evident that most of the people who inhabited Scotland in the first millenium did not come from Ireland. By tradition one of the peoples (ie the Scotti) who came to make up the Scots of the later Scottish nation came from Ireland. By tradition they came across with King Fergus about 500AD. Most Scottish historians now seen to concede that this could simply be a change of power base from Ulster to Argyll and that Dalriadan influence itself traversed the Irish Sea and that there would already have been a Gaelic speaking population in Argyll prior to his supposed arrival. There isn't any proof of any violent mass invasion which leaves the possibilities that there may have been a trickle movement over time; there may simply have been a Gaelicisation of the upper stratums of society which eventually led to cultural dominance; or the Epidii of the early 1st millenium may have already been Gaels with no need for any movement from Ireland. In truth we don't know for sure! They either came from Ireland originally or were simply already part of a greater Irish (or at least Dalriadan)cultural area. Either way the Gaelic language then spread over most of the rest of Scotland to at least some degree.