Alphonso X Book of Games 13th century C.E.

3 Six pointed stars on the bottom and top margins of the chess board 

Picture from Fol 9r

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Six pointed stars appear several times in Alphonso X's [amazing] Book of Games 

(Book of chess, dice and tables -Libro de los juegos

Written and painted in Toledo, Spain, 1283 C.E.

Researchers argue if the apearance of this symbol has any connection to Jews 

Chi Rho Six Pointed Star

Chi Rho (1870) carved in stone at the Russian Compound in Jerusalem 

The Chi Rho was used by early christians. It is called after the names of the first two Greek letters Chi and Rho (ΧΡ). These letters start the word "ΧΡΙΣΤΟΣ" =Christ. The  letter on the right is Alpha and the letter on the left is Omega. The term Alpha and Omega comes from the phrase "I am the alpha and the omega"  in the Book of Revelation (1:8) which means that Jeusu is the First and the Last, the beginning and the End, since Alpha is the first and Omega is the last letter of the Greek alphabet.

The beginning of this symbol is ascribed to Roman emperor Constantine (272- 312 C.E.) who called it labarum and used it as a military symbol.

There is no unequivocal proof that Constantine invented the Chi Rho and that he started its usage as a military symbol, but it is interesting to compare his legend to those about the beginnings of the star of David and the Fleur de Lis. Constantine and King David both won wars by inscribing their emblems on their shields. In 493 King Clovis I got the Fleur de Lis emblem from God, after his conversion to Christianity… like Constantine. In all three legends kings start the history of a symbol. These three symbols are actually three aspects of the same six-pointed star symbol (Fleur de Lis is a six-pointed star viewed from the side). 
The same goes for Solomon's Seal symbol which started from King Solomon . The name "Solomon's Seal" was used during the Middle Ages to mark  stars with five or six points. 

Researchers Aarne and Thompson in their typology of International Folktales proved that the same legend may appear in different cultures without any known connections between their inventors, and it seems to me that this is the case here. Usage of these symbols did not start  from historical events but from the need of folk consciousness to attribute the beginning to a supreme source of authority - a king by the grace of God.

Roman Mosaic. Center: Chi Rho 4th Century 

CC Image from Wikipedia entry: Hinton St Mary Mosaic 

The Chi Rho is flanked by two pomegranates

It is interesting to notice that in any pomegranate before the crown

(Six pointed Star) opens it looks like Six Radiuses with a common center, 

just like the Chi Rho 

View my Chi Rho Christogram Six Pointed Star Gallery on Flickr