The clue is in the appelation 'of Troyes'.
- Troyes had been the home of the famous Rabbi, Rashi, who is renowned for his incisive commentaries on the Hebrew Torah.
- Troyes was where the Church Council was held that gave the Templars their official Ordo status. This was attended by Stephen Harding, the English Cistercian monk whose chief claim to fame was his expertise in translating Hebrew texts.
- Troyes was the origin of the Templars, who were posted to Jerusalem, where they mingled with indigenous Jews, some no doubt with expertise in ancient Hebrew (in fact the only kind of Hebrew to exist at that time, as it was a dead language).
Chretien of Troyes was the first person ever to use the term Graal (Grail) explicitly, a practise that was taken up by Wolfram von Eschenbach. Though they wrote about the Grail in very similar terms, there are important differences that the Genesis Seal is able to bridge.
Both the Templars and the Cathars were reputed to possess fabulous treasures with the common characteristic that they included ancient manuscripts that some commentators suggest were Hebrew. The Cathar treasure was also said to include the Holy Grail, while that of the Templars included the Ark of the Covenant and other artifacts of Solomon's Temple. It is more likely the treasures (apart from the manuscripts) were a smoke-screen created by the Church, or to help in recruiting to the Albigensian Crusade against the Cathars.
This is a rushed summary, but fits the known facts while filling in some long-standing historical enigmas.