The modern understanding, that of griffons tied to the land in personal relationship with their liege lord, emerged in and around two thousand years ago when griffons ceased being exclusively herders and hunters and started being more agrarian like their neighbouring races. This had the added benefits of bringing griffon settlements off the mountain tops, the expansion of mining, and other civilizational development. Although he'd have to ask someone about it, the All-Maker cult began rising to prominence not long after the civilizational shift.