I've read recently that when the French were exploring the length of the Mississippi they asked the Indians living on what is now the Dubuque River what the name of the people upstream was. The reply, rendered as "dubuque" actually means "shit faces."

Jews were called "Christ killers" in the Middle Ages, Shakespeare uses the word "frogs" to mean the French in his plays, and I suspect that the Celts branded the Roman soldiers in the same way that US soldiers in 'Nam and Korea called the enemy* "gooks." In the UK it was an insult in some areas during the 18th C. to call someone a Tory; earlier there were the "Roundheads" and later in Ireland the "croppies".

Heck, ever the sports teams at the University of Notre Dame were called "Fighting Irish" -- and it wasn't a compliment at the time.






*Enemy: someone who is trying like heck to do you grievous bodily harm.