of Celtic.
The Gaels during the beginning of the Christian era (at which time Gaelic people were mostly restricted to Ireland) believed themselves to be descendants of Míl Espáine coming from the north of Iberia, mainly Gallaecia (modern Galicia and northern Portugal), where there existed also an early form of Ogham script in Gallaecia, as well as genetic studies linking the Gaels to the Basques in northwestern Spain. This belief persists in the Gaelic cultures of Ireland and Scotland up to the present day, with many if not most clan leaders in either country claiming descent from their predecessor, back to famous historical kings going back into pre-history.
The first people to arrive about 7,000 years ago the Connemara mountains were small bands of hunter-gatherers. Estimates of the arrival of Goídeleg in Ireland from the Neolithic vary widely from the introduction of agriculture circa 4000 BC to Lower Egypt around the first few centuries BC to the Iron Age or Celtic period. Lake forts (Crannógs) are a distinctive feature of the Connemara lakes and island forts are also found all along the west coast and in the Outer Hebrides off the Scottish west coast.
Celtic-speaking peoples once ranged across most of northern Europe, from Ireland to the Ukraine, and as far south as the Iberian peninsula and Asia Minor. But the expansion of both the Romans and the Germanic peoples pushed the Celtic world increasingly into the northwestern fringes of Europe, and after Caesar's conquest of Gaul in the first century BC, the only autonomous Celtic-speakers were those living in the British Isles. These Celts too were threatened by both Romans and Germans.
Goidelic languages (Deer) were once restricted to Ireland, but sometime between the 3rd century and the 6th century a group of the Irish Celts known to the Romans as Scoti began migrating from Ireland [the Uladh of Emain Macha and Armagh, Lurg, Cashel] and Dal Riada to what is now Scotland and eventually assimilated the Picts. In the time of Ptolemy, Tyrone or Tir-owen was inhabited by the Scoti, which tribe extended itself over most of the inland regions; though some writers place the Erdini here, as well as in the neighboring maritime county of Donegal.The Goidelic branch is also known as Q-Celtic such as Ogham to Gaelic, retained this branch of Celtic when the sound change, found in Celtiberian and Gaulish as well as collectively P-Celtic occuring had identical sound shift (Q to P) independently in the predecessors of Gaulish and Brythonic such as Illyrian and Pictish.
Before and during the age of the Roman Empire there was a great deal of movement, interaction and competition among the peoples referred to collectively as the Celts; Iron Age Europe can perhaps be best understood as a cultural foment. The Novantae Celtic tribe in Galloway was based in the Rhins area and were known to the Romans as trading partners. In later times the area became part of numerous kingdoms that ruled in the wider region, including Gododdin, Rheged, Strathclyde and Bernicia.
The Gaels are an ethno-linguistic group in Ireland, Scotland and the Isle of Man, whose language is one that is Gaelic (Goidelic), a division of Insular Celtic languages. They arrived in Ireland sometime during the first century B.C., and brought a distinctive language, the ancestor of modern Gaelic, which would come to dominate the hybridized Gaelic culture that emerged from the prehistoric melting pot of Ireland (hence the later general appellation "Gaels" which was applied to all Gaelic-speaking people of Ireland—and later Scotland).
The emperor Claudius began the Roman conquest of lowland Britain in AD 43, after which the Britons, like the Gauls, became in varying degrees Romanized. No sooner did they gain their political independence from Rome, in AD 410, than did they face a serious threat from Germanic-speaking raiders living along the North Sea. These peoples, including the Angles and the Saxons, first arrived in Britain as mercenaries, and would eventually come to dominate the same lowland regions that the Romans had conquered and give that land a new name--England.
The Britons came from three very powerful Germanic tribes, the Saxons, Angles, and Jutes. The people of Kent and the inhabitants of the Isle of Wight are of Jutish origin and also those opposite the Isle of Wight, that part of the kingdom of Wessex which is still today called the nation of the Jutes. It is not known with any certainty when speakers of a Goidelic (or Q-Celtic) language reached Ireland, or how they came to be the dominant culture, or if Q-Celtic didn't develop entirely in Ireland from a previous dialect.
The Irish invaders, the original Scotic tribes, were successful throughout the Western borders of Scotland, or Alba as it was then known, as they had only a sparse population to contend with, but were repelled to a great extent throughout the rest of the country; the paradox of tribal warfare between the Gaelic speaking Q Celts and the Picts in Skye, and at the same time a gradual coalescing of both branches of the church on the island, a mirror of happenings on the Scottish mainland. The distant cultures point to Skye's involvement in this heroic age of the Gaelic speaking people. The Gaelic people from Ireland, probably a mixture of P and Q Celts, began to raid the Western coasts of Britain. Some believe Goidelic replaced some pre-existing Brythonic (or P-Celtic) language(s), but it is not known whether this represents one population displacing others, an invader becoming a new ruling caste, or simply the spread of a new lingua franca.