gender and dual number. The two groups also differed in the matter of initial mutation and aspiration. There is the famous substitution of “P” for “Q” in the Brythonic languages—hence the designation of “P” Celtic and “Q” Celtic. Thus the word “head” in Irish, ceann, becomes pen in Welsh; the word “worm” in Irish, cruimh, becomes pryf in Welsh, and so forth.

The Celts dominated Northern Italy for a time, defeating the Etruscan empire and then Rome itself in ca. 390–387 b.c. Other Celtic tribes pushed further east and were met by Alexander the Great on the Danube in 335–334 b.c. in a peaceful conference. Not until after Alexander’s death did the Celts invade Greece and sack the holy shrine at Delphi, pressing on to establish the state of Galatia on the central plain of Turkey. It is the Galatian state that provides us with our first accounts of how a Celtic state was governed.

It was in the third century b.c. that the Celts achieved their greatest expansion before the rise of Rome halted them and they, in turn, began to be pressed backwards by Roman expansion. Defeating the Celts of Northern Italy, then Spain, the Roman legions pushed into Gaul. At the same time the eastern Celtic areas in Rumania, the Balkans, Czechoslovakia, Austria, and Switzerland were being conquered and the people absorbed. The Galatian state also fell to Rome, although Gaulish Celtic was still spoken there, according to St. Jerome, who visited Ancyra (Ankara), which was a Celtic capital.

The Celts were an exciting and inventive civilisation with a highly developed religion that unified all their tribes from Ireland to Galatia. They had a sophisticated law system and were among the first to develop the concept of immortality of the soul, a fact that made the change to Christianity an easy process with, significantly, no Celtic martyrs being registered in the change. The Greeks Aristotle, Sotion, and Clement acknowledged that much of early Greek philosophy was influenced by the Celtic druids. The Celts of Cisalpine Gaul (northern Italy) and many from Spain actually contributed to Latin literature. Being forbidden to write in their own languages by religious prohibition, they wrote in Latin. Writers such as Gaius Valerius Catullus, Valerius Cato, M. Terentius Varro, Caecilius Statius, Lucius Pomponius, Cornelius Nepos, Trogus Pompeius, the famous Virgil, and many others