Board Thread:Theories/@comment-29900084-20161008030717/@comment-27441457-20161103194938

I've got a good feeling that the ancient Fritz family is the same as the modern Reiss family, just under a new name, since the 145th Fritz King was also the First Reiss King.

But Eren wouldn't be related to Ymir and Historia. Zeke's royal blood comes from his mother Dina Fritz, while Eren's mother Carla wasn't related to the Fritz bloodline.