The Knights Templar were a religious military order founded about 1118 at Jerusalem by the European Crusaders who had invaded and recaptured the Holy Land. There are millions of pages written about the Templars and their ties to Masonic rituals and their connection to the Holy Blood, Holy Grail theory that was introduced in the first issue. Matt's used a little creative license to move the founding of the order back a few centuries. The templars are very important to the story, so more will be revealed as the story rolls along.