Who were the Celtic peoples?

The Celts were a group of peoples that occupied lands stretching from the British Isles to Gallatia. The Celts had many dealings with other cultures that bordered the lands occupied by these peoples, and even though there is no written record of the Celts stemming from their own documents, we can piece together a fair picture of them from archeological evidence as well as historical accounts from other cultures. The first historical recorded encounter of …

…shouted in chorus with their] deep and harsh voices, they beat their swords rythmically against their shields. Diodorus also describes how the Celts cut off their enemies' heads and nailed them over the doors of their huts, as Diodorus states: In exactly the same way as hunters do with their skulls of the animals they have slain...they preserved the heads of their most high-ranking victims in cedar oil, keeping them carefully in wooden boxes.