So how about those Celts? They existed in parallel with the Greeks, Romans, Germanic and Norse tribes (not forgetting peoples of Central Asia, e.g. the Slavs and Turkic peoples). There is still a lot of mystery and perhaps some misinformation, but such happens with an incomplete or partial record. One statement I found - "By the time the Celts first appear in history in the 6th century BC, they were already the dominant people of western and central Europe." "Great migrations carried the Celts into Italy, the Balkans, Greece and as far east as the steppes of Ukraine and across the Bosporus to settle in Asia Minor (Anatolia). Smaller groups served as mercenaries for Greek rulers in Italy, Syria and Egypt. Although living as separate tribes, the Celts shared a common culture. Among the population were skilled farmers and metalworkers. The "Atlas of the Celtic World" divides the discussion into the Continental Celts and the Atlantic Celts, the latter including Britain (England) and Ireland, then finishes with a discussion of modern Celts.