The earliest archaeological evidence associated with the Celts places them in what is now France and western Germany in the late Bronze Age around 1200 BC. The Celts, around 500 BC, are first recorded as controlling central Europe, beyond Spain near the source of the Danube. They were also referred to as Hyperboreans. They were said to have been a just, war-like power, but also drunken and combative. There are no surviving chronicles of their own, no architectural remains, and just a few examples of coins, weapons and jewellery.

The idea of the Celts as a tall, fair haired race is unlikely. To the Greeks and Romans, who were responsible for much of the historical record of the time, there were many types of 'Fair' and for the Celts this probably referred to 'red, brown or golden hair'. Also there are accounts of the Celts bleaching their hair with lime.

The Celts took control of areas peacefully if possible, by force if not, and introduced and mixed their beliefs, language and arts with that of the local inhabitants. The true Celts probably formed a ruling or noble class. Along with the Greeks, their allies, their sphere of influence was huge.

In 500 BC they took Spain from the Carthaginians. At the peak of their civilisation, around 400 BC, under a king named Livy Ambicatus, they controlled most of Europe including Britain and Ireland. They allied with Rome and took northern Italy from the Etruscans but, when the Romans betrayed them, immediately marched for Rome and, on July 30 390 BC, defeated the Roman Army. They held Rome for almost a year until the Romans paid compensation. A peace treaty between the Celts and Romans followed which lasted for nearly a century.

Around 300 BC, German tribes within the Celtic empire revolted. The Celtic tribes split and fought amongst themselves, with the German tribes and with Rome. Minor squabbles became major disputes and when the dust settled the only areas still under Celtic control were Gaul, Ireland and Britain.

With the Roman invasion of Gaul and Britain in the early Christian era, the remaining Celts were either absorbed into the new culture or pushed to the margins of the Roman territory. Their cultural influence remains strongest in these marginal lands.