Reliability of author Hubert Cole?

[miscreant]

Is anyone familiar with an author named Hubert Cole. He's done quite a few historical biographies and the one that I'm reading right now (The Black Prince) has a lot of details that I've never heard before from the 7 other biographies that I've read on BP. It's an old out of print book, but he doesn't have a bibliography for his sources. Very good writing style and presentation, but I'm concerned that he may rely on assumed history or beefing up the true story, such as an Allison Weir (by the way Chef, I got verification from a source in England on your thoughts on Ms. Weir.) So does anyone out there know anything of his reliability?