Refers to the three families of Einzbern, Makiri, and Tohsaka, which collectively created the Holy Grail War system around 200 years ago. The system was largely created by Justeaze Lizrich von Einzbern, Makiri Zolgen, and Tohsaka Nagato, who headed their families at the time. The families combined their secret techniques to develop the system to give structure and summon a Holy Grail capable of serving as a wish granting machine with the aim of enabling man to evolve to escape the bonds of the material body, and ascend to be higher dimension beings, or “souls” that do not require a physical body to serve as an medium or output device. Of course, once it became apparent that the Holy Grail would only grant one person their wish, they began to fight, which ultimately gave rise to the Holy Grail War. From this background, members of the Three Founding Families are given priority for selection as Masters to participate in the Holy Grail War.