The University of Nalanda c20.3

c20.3

Now this theory and the various Tāntric practices are for the first time given in their complete form in the *Guhyasamāja Tantra*¹, though there are earlier works, *Mañjuśrīmūlakalpa*, for instance, which make some stray references to this theory. The *Guhyasamāja* is assigned to the 3rd century A.D.² So the theory of Dhyāni Buddhas dates back at least to that period.