When I was a kid, I wished I was Irish. My paternal Grandfather was Scottish, and many of his people had come from the Highland coasts closest to Ireland. I remember asking my parents, "Look how close the southwest coast of Scotland is to Ireland! Don't you think that people must have traveled back and forth by boat?" I was told "No, that's ridiculous. Your ancestors were Scottish, not Irish." So as put-out as I felt about the wise parental response, I put my childish fancy aside.
30 years later, delving deep into ancestral research and Scottish and Irish history, I discovered that not only were the Highland Scottish from Ireland, ("Scot" was in fact was a name for Irish people), but the Medieval Kingdom of Dalriata encompassed both SW Scotland and Northern Ireland. People today think of seas and rivers as barriers or borders. But in a time when boats were the main method of travel, they functioned more like highways, connecting communities rather than isolating them. I have also researched some of my Scottish family names, and have successfully traced some of them back to Ireland--even connecting one family line to ancient Irish mythology, and the Tuatha de Danann. (In How the Irish Saved Civilization, author Thomas Cahill comments "In the western world, the antiquity of Irish lineages is exceeded only by that of the Jews", Pg. 123).
But the further back you go, the more things get complicated. The Lebor GabÃ¡la Ã‰renn, or Book of Invasions talks of many different waves of people who came to Ireland, conquering, displacing or mixing with the resident population. The book is vague and fantastically written, but many scholars still give it credit for containing some degree of truth.
What I have been wondering though, is how much those different invasions correlate with the different "Ages" or prehistoric periods. Huge changes in culture and technology in Ireland could easily have been triggered by incoming waves of people.
Let's consider this theory, and start with the Formorians. The original Mesolithic hunter-gatherer population of what we call Ireland would have moved there from Europe, at the end of the Ice Age, 10,000-20,000 years ago. Before the retreat of the ice, they had probably survived in the Iberian Ice Age Refuge. But before then they would have migrated from Africa. The term "Moor" was used until more modern times in Europe to refer to people of a dark complexion, and it is easy to see a connection between the words Moor and For-moor-ian.
Next came the Fir Bolg, or "Men of Bags". They were said to be carriers of bags of dirt, and it was said that they taught the later-arriving Tuatha de Danann how to farm. So it seems very reasonable to assume that they were the farmers who ushered in the Irish Neolithic Era, 5,000-10,000 years ago. The bags might have contained seeds, or perhaps dirt from their homelands as a way of carrying the spirits of the land with them. DNA research has found connections between the Middle East and the spread of agriculture, so perhaps that is where they originated from. The Formorians and Fir Bolg intermarried.
After that came the pale, red haired Tuatha de Danann, which likely correlates with the arrival of the Bronze Age, 3,000-5,000 years ago. There are dozens of theories about origin of the Tuatha, some less far fetched than others. But if they brought bronze technology with them, the time frame of Irish Bronze Age excavations also correlates with the appearance of the lactose-tolerance gene in Ireland, predominantly an Indo-European trait. Interestingly, the same time period also correlates with the red-haired tartan-wearing mummies of the Hallstatt mines, and red-haired tartan-wearing Tarim mummies of China. Did the Tuatha build the stone monuments? Stonehenge 1 and 2, Skarabrae and Newgrange were built 4,500 to 5,200 years ago, so it is very likely. What of the Tuatha losing to the Formorians and being consigned to the underworld? It's hard to say, but the fact is, that many of the family names of the Tuatha are still carried by many Irish and Scottish clans today.
Finally the Sons of Mil (also known as Milesians or Celtiberians) arrived, 2,000 to 3,000 years ago from Iberia (Spain), heralding the arrival of the Iron Age in Ireland. They also settled Britain, likely pushing the indigenous Picts to the north.
The Celtic languages were supposed to have arrived in Ireland 2,300 to 4,000 years ago, but there are two different branches of Celtic language in Ireland and Britain. Perhaps the Tuatha brought the Goidelic or Q-Celtic language, (now divided into Irish, Scottish Gaelic, and Manx), and the Milesians brought the Brytonic or P-Celtic language, (now known as Cornish, Welsh and the the extinct Cumbric and continental Gaulish languages)
I am interested in discussing these ideas with anyone else researching their Irish roots, or Irish pre-history.