'Celtic' from the Greek word 'Keltoi' (hence it is always pronounced with a hard 'C')
was used to refer to certain tribes of people that shared a common language and culture. It literally means 'secret people'.
Welcome to the mystery
'Celtic' denoted a people who are from one of the current approximately nine Celtic Celtic "fringe" areas of western Europe: Brittany, Cornwall, Galicia, Irealand, Isle of Man, Northern Italy, Portugal, Scotland and Wales.
The Celts were the first civilization north of the European Alps to emerge into recorded history. At the time of their greatest expansion, in the 3rd century bce, the Celts stretched from Ireland in the west, through to the central plain of Turkey in the east; north from Belgium, down to Cadiz in southern Spain and across the Alps into the Po Valley of Italy. They even impinged on areas of Poland and the Ukraine and, if the amazing recent discoveries of mummies in China’s province of Xinjiang are linked with the Tocharian texts, they even moved as far east as the area north of Tibet.
The once great Celtic civilization is today represented only by the modern Irish, Manx and Scots, and the Welsh, Cornish and Bretons. Today on the northwest fringes of Europe cling the survivors of centuries of attempted conquest and “ethnic cleansing” by Rome and its imperial descendants. But of the sixteen million people who make up those populations, only 2.5 million now speak a Celtic language as their mother tongue.
Ancient and Prehistory
The oldest archaeological remnants of Celtic culture can be found close to Eastern France, Northern Iraly, Southern Germany, Belgium, Northern Switzerland, Austria, Spain and an Eastern European band extending from the Baltic to Turkey.
Since Celtic people were pushed to the border of western civilization, Celtic culture can still offer the richness of a world that is egalitarian, diverse, and intimately connected with nature.