Tantra and yoga developed alongside one another rather than as fully separate traditions, and scholars such as Geoffrey Samuel have argued that many practices later associated distinctly with hatha yoga, including subtle-body cosmology, mantra and specific bodily techniques, have their proximate origins in tantric ritual and meditation rather than in the earlier, more philosophical yoga of Patanjali.
Buddhist tantra spread from India into Tibet from roughly the eighth century onward and became foundational to Vajrayana Buddhism there, carried by lineages of teachers whose transmission is understood within Tibetan Buddhism as unbroken from Indian masters, a claim that is a matter of religious lineage rather than independently verifiable history in every link.
Tantric Buddhism also reached China and, through the monk Kukai in the ninth century, Japan, where it developed into the Shingon esoteric tradition. Tantra's reputation outside its own traditions has been shaped disproportionately by its minority transgressive currents and by colonial-era and later popular accounts that treated tantra chiefly as a doctrine of ritualized sexuality, a framing scholarship considers a significant distortion of a tradition whose bulk concerns deity worship, mantra, ritual and meditation within an initiatory structure. Contemporary popular use of the word tantra, especially in the phrase tantric sex current in Western wellness culture, draws loosely on this minority current and on nineteenth and twentieth century Western esoteric reinterpretation, and bears a contested and often quite distant relationship to the textual tantric traditions of India and Tibet.