This chapter presents a bit of a disconnect between culture and genetics. The west coast of Ireland, and in particular the Aran Islands, has often been regarded as having very traditional Irish culture. Comparisons of populations with similar cultural and physical environments can control to some extent for environmental variation. In the case, the culture of the Irish Travellers suggested a link with Roma populations. The Irish Travellers live in small groups, usually consisting of several extended families. In Ireland, the itinerant population is known as the Irish Travellers, formerly referred to as the Irish Tinkers. Genetically, the Irish Travellers are not Roma but simply Irish. Genetic data can provide much more detail. The complex history of invasion and settlement, combined with the more dramatic changes in population size, make Ireland an interesting place to explore the relationship between history and genetic variation.