Esoteric Buddhism emerged between the fall of the Gupta-Vākāṭaka hegemony (ca 550 CE) up to the rise of the three great powers (Pāla, Rāṣṭṛakūṭa, Pratīhāra) in the mid eighth century, becoming Indian Buddhism’s richest ritual expression. Scholars of Śaivism have somewhat prematurely dubbed the entire early medieval period (ca 550-1200 CE) the ‘Śaiva Age,’ but that designation is predominantly true with respect to royal affiliation, less so for the culture at large as may be seen in the donative inscriptions and popular literature, which do not reflect Śaiva cultural dominance in the manner portrayed. Similarly, the depiction of later Buddhism as ‘brahmanized’ has inaccurately represented the selective uptake and modification of brahmanical rituals or the sociology of Buddhist engagement. Rather, this was the age of internecine warfare at the local and regional levels, with a dramatic erosion of social controls. The belligerence of the period precipitated the decline of national trading cooperatives, the rise of regional networks, and the emergence of marginalized groups and ritual systems. Within this era, Buddhist authors and institutions operated with bewilderingly complex resources—intellectual, ritual, artistic, social, linguistic, etc.—that revealed a spectrum of engagements, from accommodation to resistance and everything in between.
Esoteric Buddhist myths and rituals reflect to some extent these developments, so that the bodhisattva as sārthavāha (caravan master) becomes replaced by the bodhisattva as vidyādhara (sorcerer), signaling the change in models of agency from the mercantile to the magical. The earliest corpora of literature—that of the Amoghapāśa on one hand and the Uṣṇīṣa texts on the other—were constructed on the earlier dhāraṇī texts of the fifth and sixth centuries, as seen in the Chinese translations from the Liáng Dynasty to the Táng. Yet both the Uṣṇīṣa and Amoghapāśa materials reveal further ritual directions that will be more robustly expressed in the eighth and ninth centuries, with the development of the Vajroṣṇīṣa canon and the Yoganiruttara and Yoginī tantras. These included aspects of Śaivism and Vaiṣṇavism, to be sure, but also rituals from local spirit cults, lineages of magicians, gṛhya rituals from domestic brahmanical priests, material from the solar cult, to name but the most significant sources.
For esoteric Buddhism, the most important early region was that of the Vārāṇasī- Pātaliputra-Gāyā triangle, with its multiplicity of Buddhist sites and intermittent institutional support. Other centers, however, quickly arose—each with its own rituals and lore—and by the end of the eighth century most of North India had developed independent centers of esoteric practice, spreading thence to Śrī Laṅka and Śrīvijaya, as well as to Tibet, Nepal and East Asia. The speed and urgency of esoteric missionary activity in South and Southeast Asia are markers of a new dynamic.