On the issue of ancient place-names, it is generally accepted that "Aber" is an ancient P-Celtic Brittonic word meaning "mouth of a river/estuary" and that "Inver" is a Gaelic equivalent. That isn't controversial e.g. From Wikipedia https://en.wikipedia.org/wiki/Aber_and_Inver_(placename_elements) .......
Well, that word, "Inver" is from Gaelic, not Irish. People were living in Ireland and speaking a language that was NOT Gaelic, for millennia before the Gaels, with their weird archaic Q-Celtic (Basque?) language, arrived in Ireland in Christian times. Haughey's Fort, the ringfort just a mile from The Ancient Capital of Ulster at Emain Macha contained artefacts dating from 1100 BC, long before the Roman Empire was even a twinkle in Romulus's eye, and even longer before the words "Celt" or "Gael" were ever used. The people who built Ireland, who built the passage tombs at Slieve Gullion and Newgrange, who traded with the European Aristocracy during the Bronze Age, and into the early Iron Age, were not Gaels, and they had their own languages.
"Ireland tends instead to have names with béal ('mouth') in such locations, as Béal Átha na Sluaighe (Ballinasloe, Co. Galway), Béal an Átha an Fheá (Ballina, Co. Mayo) or Béal Feirste (Belfast). The difference in usage may be explained by the fact that Gaelic names in Ireland are typically a thousand years older than those in Scotland[citation needed], and hence the prevailing fashion could have been different.
Sigh!!! There is a much simpler explanation. Many or most ancient Irish place names are not "Gaelic" and predate the Gaels by millennia. The Gaels appear to have arrived in Galway in Roman/Christian times. I refer back to Ptolemy's "Geographia" which shows the ancient capital of Ulster at Emain Macha (not Gaelic) and "another capital" at Turoe (likely start of the Gaelic invasion).
"Aber" place names are more common in parts of the British Isles where the European languages used during the Bronze Age (starting around 3000-2500 BC in Ireland?) and Iron Age (starting about 800BC?) had not been completely supplanted by the "Gaelic" language of the foreign invaders. That language appears to have spread through today's Connaught in Roman times, and was carried into South Western Scotland by the people in North Eastern Ireland who had had to learn the foreign language and were moving their capital of Dal Riata from Dun Severick in Antrim, to Scotland, under pressure from the invading Gaels.
The people living in Western Britain around that time were called "Wealas" by the Saxons invading from the East - "Wealas" - "the people who are not Saxon". The term included the P-Celtic-speaking "Britons" in their heartlands around Dun Edin (Edinburgh) Dun Bretain (Dumbarton), Cumbria, and Cymru, names derived from the term "combrogi" meaning "the brotherhood". Eventually the term "Wealas/Welsh" became restricted to the people living in the country now known as "Wales" still called "Cymru" by the ancient Britons who live there and still speak a P-Celtic language. So, it is not surprising that place-names beginning with "Aber" are common in Wales, the last refuge of the ancient Britons, and are more common in North Eastern Scotland - the furthest away from the invading Gaels with their "Inver" term. As an aside, the term "Sassenach" was used by Gaelic-speaking Scots to refer to the Saxons.
Despite the Gaelic invasion, the North of Ireland still maintained pre-Gaelic place names such as "Beal Feirste" - Belfast, which was deep in the heartlands of the Cruthin and Ulaid, the last part of Ireland to come under Gaelic rule, in the
According to accounts of the meeting between the the Gaelic Ui Neill (Christian) Prince "St Columba" and the pagan P-Celtic-speaking Cruthin in North Western Ireland, (written down by Gaelic Monks centuries later), a translator was required (references to be added). That doesn't accurately establish a date when the Q-Celtic Gaelic started supplanting the P-Celtic language in the British Isles but, it firmly places the arrival of Gaelic in Christian times. For whatever reason, the "Gaelic Q-Celtic language" became the language of power, just as, later, "English" was adopted as the language of power in Ireland. English became the language of Power, not just in today's USA, Canada, Australia, New Zealand, but also in India, where the vast majority of the population spoke a number of different languages. Adoption of a foreign language of power, through necessity, says nothing about the ethnicity of the people who had to learn to speak it, nor their culture, nor their beliefs. And that includes the adoption of the archaic Q-Celtic "Gaelic" language in the British Isles in Christian times.
The Gaels themselves said that when they arrived in Ireland, the region they landed in was held by people they called the Fir Bolg (in Celtic language). In his book “Early Irish History and Mythology” first published in 1946, respected Irish Linguist and Historian T.F. O’Rahilly made a convincing, and obvious, argument that the “Fir Bolg” were synonymous with the people known to Julius Caesar by the Latin name “Belgae” i.e. the Fir Bolg were the men (Fir) who came from the area now known as Belgium.
The “solution” used by Gaelic historians to get around this unpalatable fact when history was being written down in the 8th and 9th centuries was simply to make the Fir Bolg a “mythical people” thus removing that reference point in history, allowing them to concoct a fiction with Tara as the seat of an ancient line of Gaelic "High Kings of all Ireland" (of whom there is no credible historical reference), rather than a seat of the Northern Cruthin/Ulaid Kings of Ulster, for which there is much stronger evidence. To do this they had to dissociate the Irish term Fir Bolg (Fir = Men) from the Belgae and did so by claiming that the term Bolg was derived from the Irish word for belly, bag, or sack. The notion that people would refer to themselves as the Fir (men) of the belly/bag/sack, or even breeches, or that others gave them that name, as has been suggested, seems far-fetched compared to simply referring to themselves as the men of the Belgae/Bolg. Of course this fiction frequently ran into problems, for example with the type of spear called Gae Bolg, or Gae Bulga (Gae = spear), which is mentioned frequently in writings about that era. To be consistent, this now had to be called a “belly spear”, or a "bag spear" etc, which is a little odd since it appears to have been a barbed throwing spear, rather than a thrusting spear. The alternate explanation is that this was just a type of spear used by the Fir Bolg, and therefore a Belgic Spear – Gae Bolg. Amongst competing theories, the simplest one, the one that requires fewest assumptions, is usually the right one. In any case, the fiction took hold. The Cruthin were given a mythical Gaelic ancestry, the Fir Bolg were ignored, and Ireland became “an ancient Gaelic nation, united under Gaelic Kings based at Tara”.
This “work-around” might have fooled people in the 8th Century but does not stand close scrutiny in the 21st Century, or at least it should not. However, the lie continues to have traction to this day, and was even incorporated into a recent study of Irish Genetics by Professor Brian Sykes, who, in his book “Saxons, Vikings, and Celts” took it at face value and ignored any contribution to the genetics of Ireland by the Fir Bolg, dismissing them as a “mythical people”. The people responsible for this elaborate deceit have done a disservice to all Irish people, by denying the realities of Irish History, including denying the existence of the Fir Bolg, one of the most important peoples to arrive in Ireland. We learn history to avoid repeating the mistakes of the past, but if the very history that is taught has been falsified to support a particular point of view, then it is at best worthless, and at worst, harmful.
So, in the absence of any information to the contrary, it seems reasonable to assume that the people Julius described as "born in the island itself" in 54BC contained a large element of the Pretani/Cruthin referred to by Pytheas in 325 BC, and that there had clearly been significant incursions into Britain (and Ireland) by Belgae/Fir Bolg by the time of Julius’s invasion of Britain.
In fact many scholars believe that Julius Caesar's invasion was motivated at least in part by his determination to pursue a particular Belgic tribe the Romans called the Manapii (Fir Managh, or Fir Monagh in Celtic), who had refused to submit to him during his conquest of Gaul, and had fled to Britain instead. The first map of Ireland, drawn up by Ptolemy, shows Manapii in SE Ireland. It also shows the Iverni and Voluntii (believed to be synonymous with the Ulaid, ). The Manapii/Fir Managh left their mark on the British Isles in the places named after them, including the Isle of Man, counties Fermanagh (Fir Managh) and Monaghan, Dunamanagh (Dun = Fort, of the Managh) and many others. Since the Fir Managh were Belgae, they were Fir Bolg, and places are generally not named after mythical peoples, not even in Ireland. Furthermore, the descendants of the families Mooney, Meaney, Meeny, McWeeney, Monaghan, Monahan, Mannion, Manning, Mongan, Mangan, Minogue, Minnock, Mannix, Manahan, Mongey, Mongavin, McMannion, McMenamin, McMonagle, Marannan and Murnane, all derived from the Fir Managh, (See The Menapia Quest, by Norman Mongan) might be surprised to learn that they are fictitious people too.
The first map of Ireland was prepared by Claudius Ptolemy, who lived in the second century AD. His map showed two, and only two, “Regia” (Royal Site, or Capital) in Ireland. One is easily (and accurately) identified as Emain Macha, the seat of the Ulster Kings, close to present-day Armagh. The other is listed as Altera Regia (the other Regia) that some have tried to claim is Tara. Detailed mathematical analysis now places the “Other Regia” at Turoe in Galway, Connaught, NOT at Tara.
Whoever the Gaels were, the reality is that wars between the people who came to be known as Gaels, based in Connaught, and the Northern Kingdom of Ulster went on for centuries. The Gaels expanded outwards relentlessly, and eventually, sometime in the 6th Century AD succeeded in pushing into the West of Ulster, up into Donegal. The old Regia at Emain Macha was abandoned and the Ulstermen were forced East of the River Bann, into today’s Antrim and Down.
There was a global climate catastrophe around 535 AD, recorded by Nan Shi in China: the Avars (Mongolians) were forced to move West by famine and within 20 years had conquered much of the Eastern Roman Empire, the Koguryo kingdom of Korea fell, and the Toetihuacan in Mexico disappeared. British tree-ring records confirm the catastrophy, caused by a volcanic eruption, or possibly an asteroid/comet impact. The Annals of Ulster reports that there was no bread in AD 536, and other reports speak of a failure of bread from AD 536-539. Famine may have played a role in weakening the Ulster Kingdom and allowing the invaders to break through. The Ulstermen attempted to reverse the Gaelic invasion in 637 AD, but were decisively beaten at the Battle of Moira, the largest battle ever to place within the shores of Ireland. From that time onwards, the Kingdom of Ulster was confined to the land East of the Bann and the Gaels became the dominant force in Western Ulster from late 7th Century until the Norman invasion in the 12th Century.
Somewhere in all of this there has to be some basis for the myth of Gaelic "High Kings of Tara" ruling "All of Ireland" from "Time Immemorial" - but where is it? Ptolemy's Map shows no sign of a "regia" at Tara, only the Regia that was the capital of the Kingdom of Ulster, and "The Other Capital" of the invaders. There is not a shred of evidence of anything other than a centuries-long war between Ulster and the Gaels of Connaught, and the eventual fall of the Ulster Kingdom.
We are ALL British, geographically-speaking, if not politically-speaking, in the sense of being derived primarily from the gene stock of the initial Pretani/Cruthin settlers of the British Isles. It would be better for all concerned if that were more widely recognized.