Analysis of information sources in references of the Wikipedia article "ウィンザー公爵" in Japanese language version.
And then there was Windsor, which was a non-starter given that the last Duke of Windsor was the former King Edward VIII, who abdicated to marry another American divorcee, Wallis Simpson, and had some rather uncomfortable ties to the Nazis.
It was probably too early to bestow the title Duke of Windsor, as to do so would resurrect the memory of the Duchess of Windsor, Wallis Simpson, the last US divorcee to marry into the royal family, precipitating the abdication crisis of 1936.
And then there was Windsor, which was a non-starter given that the last Duke of Windsor was the former King Edward VIII, who abdicated to marry another American divorcee, Wallis Simpson, and had some rather uncomfortable ties to the Nazis.