12世纪,諾曼人(英语:Normans in Ireland)征服了爱尔兰的部分地区(导致数个世纪的冲突),而苏格兰的部分地区则被诺曼化。然而,盖尔文化在整个爱尔兰、蘇格蘭高地和加洛韦(英语:Galloway)仍然强势。17世纪初期,爱尔兰最后的盖尔王国落入英国的控制。詹姆斯一世试图征服盖尔族并消灭它们的文化。在爱尔兰,其方式是以说英语的英国定居者殖民盖尔人土地;在苏格兰高地则是通过诸如《爱奥那章程》(Statutes of Iona)等压制性法律。在接下来的几个世纪中,盖尔语受到压制,大部分被英语排挤。但是,它仍然是爱尔兰的爱尔兰语区和苏格兰的外赫布里底群岛的主要语言。盖尔人的现代后代遍布英国、美洲和大洋洲。
^Neolithic and Bronze Age migration to Ireland and establishment of the insular Atlantic genome (页面存档备份,存于互联网档案馆) "Three Bronze Age individuals from Rathlin Island (2026–1534 cal BC), including one high coverage (10.5×) genome, showed substantial Steppe genetic heritage indicating that the European population upheavals of the third millennium manifested all of the way from southern Siberia to the western ocean. This turnover invites the possibility of accompanying introduction of Indo-European, perhaps early Celtic, language. Irish Bronze Age haplotypic similarity is strongest within modern Irish, Scottish, and Welsh populations, and several important genetic variants that today show maximal or very high frequencies in Ireland appear at this horizon. These include those coding for lactase persistence, blue eye color, Y chromosome R1b haplotypes, and the hemochromatosis C282Y allele; to our knowledge, the first detection of a known Mendelian disease variant in prehistory. These findings together suggest the establishment of central attributes of the Irish genome 4,000 y ago."
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