My source was an episode of Hardcore History. I believe the population estimate he gives is 6 million (which would make sense if there were 3 million men) with

My source was an episode of Hardcore History. I believe the population estimate he gives is 6 million (which would make sense if there were 3 million men) with 2 million deaths and two million slaves. I'll give it a re-listen to see if I can find the source he was quoting from, but if anyone's heard the episode, it's the part where he's explaining why it's sometimes called the "Celtic Holocaust".