The "kindred" of Jesus and their male-line descendants were honored in very high degree both by Christians and by various Jewish interest groups alike, as heirs of ancient Jewish royalty, or as earthly representatives of "Christ", the eternal king of the universe. The descendants of The Holy Family were called the Desposyni" /"Desposynoi", meaning, "The Master's Kin". The "desposyni" took the surname "Kyriakon", meaning "The Lord's House". Their claims to be the successors of "another king", one, Jesus, other than Caesar (Acts 17:7), made them rivals of the Roman emperors, and, as such the emperors Domitian, Trajan, and Hadrian, carried out proceedings against the "Desposyn[o]i" [descendants of Christianity's "Holy Family"]. Their emblem, or coats-of-arms, varied from a depiction of the "madonna and child", to a depiction of the "paschal lamb" crucified on a cross, to a depiction of "The Holy Grail" painted on a round shield with the supporters of a lion, representing "Judah", and a "unicorn" representing the "Desposyni"; and its crest was the six-pointed "Star of David" inside the circle of the depiction of the sun shining at its splendor".
I sent David Hughes an email asking him to tell more about the "crest [that] was the six-pointed "Star of David" inside the circle. Here’s his answer:
The coat-of-arms which has two supporters, a lion and a unicorn, with the star of David inside the circle of the sun as its crest appears in the thirteenth century [or possibly as early as the eleventh century] to be the coat-of-arms of families which claimed descendant from the desposyni. There were three such families which resided in Britain according to the "Triads". The design is based on the Jewish symbol [or coat-of-arms, so to speak] of the Davidic Dynasty which derived from various Bible verses, such as judges 5:31b "as the sun when it goes forth in its might" or psalms 84:11a "is a sun and shield". There is another Bible verse where God promises David an eternal throne and links it to the sun as a symbol of His promise, which reads "His [David's] seed [dynasty] shall endure forever, and his throne as the sun before Me." I cannot recall the exact Bible verse at this time. The coat-of-arms of the Davidic Dynasty is based on that verse. I think it was invented in the sixth century BC, but not sure. It had only one supporter, which was a fierce lion, frontal view, with a crown on his head holding a round shield with the Star of David on it. Thus, one sees only the lion's head and shoulders and paws [or hands] and his feet upon which the shield rests. He also holds in one hand a scepter, and in the other hand various objects that differed from one another according to the artist's design, sometimes a sword. The lion's feet stands upon a scroll-like design upon which is written the dynasty's motto: "God, and My Right" referring to the Davidic covenant. The shield is silver and the star on the shield is gold, that is, metal on metal in medieval heraldry was reserved only for the Davidic Dynasty, for all other coat-of-arms were either color on metal or metal on color. I think the Star of David is ancient in origin, cause we know that Bar Kokhba had a shield with the Star of David on it.