While on a Junior Year Abroad program at the Hebrew University many years ago, I found a collection of family trees for the noble houses of Europe that contained a tree for the banking side of the Katzenellenbogens. On that tree, I remember seeing the surname THORNER, which was my great-grandmother's maiden name. I hadn't started researching my genealogy at the time, so I didn't record the book's title. Now that I have a tree for my THORNER ancestors going back far enough to overlap with what I recall seeing in that book, I would dearly love to access it again. Might any KATZENELLENBOGEN researchers know what it is called, and perhaps where a copy could be found?