One of the line of David, though this line was through Joseph etc.  To believe these prophesies you have to believe that Joseph was the father of Jesus ( when he probably was).

Except, of course, for the rather inconvenient fact for your argument, Boudi, that Jewishness was and is traced through one's mother's lineage.  In fact, it would also seem likely that Mary was of the line of David as well, so the status of Joseph actually becomes largely irrelevant.