This is a family tree showing the relationship of the Knights Templar, the monarchies of England and Scotland, and the origins of Arthurian Romance.  Those in Blue are kings of England.  Those in Green are kings of Scotland.  Those in Red are Kings of Jerusalem (aka the Latin Kingdom of Jerusalem).  Fulk V was not only a king of Jerusalem, but he was a Knight Templar. Moreover, Richard used Templars in his campaignes. Philip of Alsace was Chretien de Troyes' source for Perceval, or, the Story of the Grail, the first Grail Romance.  Marie de Champagne was Chretien's source for Lancelot, or the Knight of the Cart.

This isn't some sort of Holy Blood, Holy Grail idea I'm trying to put out there. But it is interesting to note the close relationships of all these people. It shows how stories can be attached to anyone.