Shallit Lecture given at BYU on March 17, 2008. The Celts living in the middle of Europe were the fearsome opponents of the Greeks and Romans and in c. 390 B.C. they actually besieged Rome. The classical writers have much to say about their warlike activities but where did they come from? Until recently it used to be thought that they emerged in Eastern France and Southern Germany and spread westwards to Spain, Brittany, Britain and Ireland taking their distinctive language with them which survives today as Breton, Welsh, Gaelic and Irish. But recent work is suggesting that the Celtic language may have developed in the Atlantic zone of Europe at a very early date, and DNA studies offer some support to this. So who were the Celts? We will explore the evidence and try to offer an answer.