As I understand it, every summer the Vikings laid on a number of cruises so they could pop across the North Sea, maybe bring back a wife or, if they were really lucky, a wife plus farm enabling them to stay and add to the gene pool. Inconvenient husbands not a problem.
Then they tired of the cabins open to the elements, so decided to travel to Paris for a bargain break. Unfortunately, the Parisians had double booked and wouldn't let them in, so they decamped to what we now call Normandy and the rest, as they say, is history.
Ironically it was William who bought the first Jews over here, but sometime later we performed our first ethnic cleansing (at York).
I'm quite sure the Nazis did have paper trail of deaths – sometimes; just been researching (for another purpose) Norway in WW2 and most of the records were destroyed, which means a total figure for the Holocaust must be an estimate.
Anyone wanting a clear idea of the losses the Russians suffered in the war (more than all of the Allies added together) read Max Hastings', 'All Hell Broke Loose'.
Like others I was taught at school how great our nation was – I'm guessing most nations do the same – and have slowly discovered things weren't quite as we'd been taught. India for example was the richest nation on the planet until we got there and managed to get a significant amount for ourselves.
I love history, mainly because it can't be changed, only our view of it can. Makes for an enjoyable thread.