Americans forget about how weird it is to have all this space to ourselves, everything I’ve learned about Irish history reflects the inconstancy and fluidity not just of what happened, but who the heck lived there. It makes other broad historical claims problematic, for instance regarding the atrocities of Oliver Cromwell in Ireland during the English Civil War. Thousands of people were slaughtered, but it was mostly mercenary soldiers from Wales, Scotland, England and the continent. To understand all the allegiances and armies, you have to spend about 30 years figuring out what the heck the 30 Year War was about.