Star of David in Parma Psater from 1280 C.E
See:
Folio 118b - Psalm 83
Thanks to Prof. Georg Eisner for referring me to this artifact
This blog (by Zeev Barkan) is dedicated to the Star of David, its history, its various meanings and usages in different cultures. It includes thousands of pictures of Star of David, six-pointed stars, hexagrams, Solomon's Seals, Magen Davids and yellow badges,and served as a resource for three books and four art exhibitions.