Udiana[1] (also: Uḍḍiyāna, Uḍḍāyāna, Udyāna or 'Oḍḍiyāna'),[a] a small region in early medieval India, is ascribed importance in the development and dissemination of Vajrayāna Buddhism.
[4][5] He came to the conclusion, drawn from his careful examination of a variety of old textual citations, that it was located near Kashmir, accepting the modern-day Swat as the probable epicentre of a historical Oddiyana.
[3] [4][5] Udyāna (Sanskrit "garden, orchard") is sometimes reported as being located north of Peshawar along the Swat River; it was regarded as the furthest part of northern ancient India during the time of Faxian.
[11] While the 6th to 8th century Kabul Ganesh offers a memorial inscription, to Turk Shahis king Khingala of Oddiyana.
[13][14] An alternate theory places its location in what is now the modern Indian state of Odisha,[16][6] through a case founded upon "literary, archeological and iconographic evidence".
Oḍḍiyāna is also the Middle Indic form of Udyāna "garden," the name by which Xuanzang knew the region around Odisha.
Sahu objects, however, and points out that these two sets of names are seldom distinguished in Buddhist Tantra literature, and opines that the words Oḍa, Oḍra, Uḍra, Oḍiviśa and Oḍiyāna are all used as variants of Uḍḍiyāna.
Also, in his famous work Jñānasiddhi, king Indrabhūti opens it with an invocation to Lord Jagannātha, a deity intimately associated with Odisha and with no other area of India.
[3] John Reynolds suggests that "perhaps Uddiyana is actually a name of a much wider geographical area than the Swat Valley alone, one embracing parts of Pakistan, Afghanistan, and even Western Tibet (Zhang Zhung).
Many lineages of Tibetan Buddhism are traced to this region, including Dzogchen (which began with the great siddha Garab Dorje).