Actually, I am asking for a specific book I read almost a decade ago, but the title slipped out of my mind. There are more than a few alternative history books centered on the invasion of the UK, but I failed to find this one. It's about a young British man who, because of his background (he is Catholic, possibly of Irish origin), joins the fascists in the Spanish Civil War, then fights for Germany in WWII, including in the invasion of Britain. His younger brother attends Eton
by ZC31