linguistic:paraphrasing, structural:reformatting
Tantras

Many of the elements found in Buddhist tantric literature are not wholly new. Earlier Mahāyāna sutras already contained some elements which are emphasized in the Tantras, such as mantras and dharani. The use of protective verses or phrases actually dates back to the Vedic period and can be seen in the early Buddhist texts, where they are termed paritta. The practice of visualization of Buddhas such as Amitābha is also seen in pre-tantric texts like the Longer Sukhāvatīvyūha Sūtra.

There are other Mahāyāna sutras which contain "proto-tantric" material such as the Gandavyuha and the Dasabhumika which might have served as a central source of visual imagery for Tantric texts. Later Mahāyāna texts like the Kāraṇḍavyūha Sūtra (c. 4th –5th century CE) expound the use of mantras such as Om mani padme hum, associated with vastly powerful beings like Avalokiteshvara. The popular Heart Sutra also includes a mantra.

Vajrayāna Buddhists developed a large corpus of texts called the Buddhist Tantras, some of which can be traced to at least the 7th century CE but might be older. The dating of the tantras is "a difficult, indeed an impossible task" according to David Snellgrove.

Some of the earliest of these texts, Kriya tantras such as the Mañjuśrī-mūla-kalpa (c. 6th century), teach the use of mantras and dharanis for mostly worldly ends including curing illness, controlling the weather and generating wealth. The Tattvasaṃgraha Tantra (Compendium of Principles), classed as a "Yoga tantra", is one of the first Buddhist tantras which focuses on liberation as opposed to worldly goals. In another early tantra, the Vajrasekhara (Vajra Peak), the influential schema of the five Buddha families is developed. Other early tantras include the Mahāvairocana Abhisaṃbodhi and the Guhyasamāja (Gathering of Secrets).

The Guhyasamāja is a Mahayoga class of Tantra, which features forms of ritual practice considered "left-hand" (vamachara) such as the use of taboo substances like alcohol, consort practices, and charnel ground practices which evoke wrathful deities. Ryujun Tajima divides the tantras into those which were "a development of Mahāyānist thought" and those "formed in a rather popular mould toward the end of the eighth century and declining into the esoterism of the left", this "left esoterism" mainly refers to the Yogini tantras and later works associated with wandering yogis. This practice survives in Tibetan Buddhism, but it is rare for this to be done with an actual person. It is more common for a yogi or yogini to use an imagined consort (a buddhist tantric deity, i.e. a yidam).

These later tantras such as the Hevajra Tantra and the Chakrasamvara are classed as " Yogini tantras" and represent the final form of development of Indian Buddhist tantras in the ninth and tenth centuries. The Kalachakra tantra developed in the 10th century. It is farthest removed from the earlier Buddhist traditions, and incorporates concepts of messianism and astrology not present elsewhere in Buddhist literature.

According to Ronald M. Davidson, the rise of Tantric Buddhism was a response to the feudal structure of Indian society in the early medieval period (ca. 500–1200 CE) which saw kings being divinized as manifestations of gods. Likewise, tantric yogis reconfigured their practice through the metaphor of being consecrated (abhiśeka) as the overlord (rājādhirāja) of a mandala palace of divine vassals, an imperial metaphor symbolizing kingly fortresses and their political power.