The “early diffusion” refers to the first period in which Buddhism entered Tibet, roughly from the seventh to the ninth centuries CE. This period roughly corresponds to the age of the Tibetan Empire, and came to an end with the chaos and destruction of the empire’s fall. The Nyingma or “ancient” tradition of Tibetan Buddhism traces its teachings and doctrines to this early diffusion. The “later diffusion” refers to a second period, roughly from the late tenth to the fourteenth centuries CE, when Buddhism re-entered Tibet, the Mahayana and Vajrayana canon was fully translated into Tibetan, and monasteries grew to cover the land. The Kagyu, Sakya, Jonang, and Geluk traditions of Tibetan Buddhism all trace their origins to this period.