The first (as far as I know) Jew to anglicize his name

I don't remember why, but yesterday a person I knew in high school a zillion years ago whose middle name was Athelstan was floating around in my mind. I knew the original Athelstan was an early English king, but I didn't know the details. So of course I Wikipedia'ed him. What I found there gave me an insight that was so astonishing, and yet so obvious, that it completely smacked my gob. It's obvious in the way that the convenience of having zero in our arithmetic is obvious now that it's been pointed out.

Æðelstān (the correct spelling) was the first Anglo-Saxon king of all of England. But here's the thing. We all know that Old English is derived from Yiddish. And Æðelstān, according to Wikipedia, means "noble stone." OK. I mean. Æðel! Noble! Edel! Right? Right? And check this out. Stān! Stone! Stein!

Yes, it's true. This King Æðelstān guy? He was in fact an Edelstein who anglicized his name. I surmise that his first name was Mel, short for melech, the Hebrew word for king. Mel Edelstein, the nice (so I assume) Jewish boy who became the first English king of England. The king of England, and yet he kept his origins hidden. Until now.

What is the significance of this discovery? Most importantly, did he pronounce his Jewish name "Edelsteen," or "Edelstyne"? Further research, beyond the scope of this post, is needed.