Künkhyen Pema Karpo (Wyl. kun mkhyen pad ma dkar po) aka Ngawang Norbu (ngag dbang nor bu) (1527-1592) was the fourth Gyalwang Drukpa. He was a great scholar and accomplished master of the Drukpa Kagyü school. Gene Smith writes, "The breadth of his scholarship and learning invites comparison with the Fifth Dalai Lama. It was [he] who systematized the teaching of the 'Brug pa sect." 
He composed 24 volumes of writings including a history of Buddhism and commentary on the Bodhicharyavatara.
There were two immediate incarnations of Künkhyen Pema Karpo: Paksam Wangpo who stayed in Tibet and Shabdrung Ngawang Namgyal (1594-1651) who went to Bhutan in 1616, where he introduced the Drukpa Kagyü teachings.
- Among Tibetan Texts, p.82
- E. Gene Smith, 'Padma dkar po and His History of Buddhism' in Among Tibetan Texts, Boston: Wisdom, 2001
- Michael Broido, 'Padma Dkar-po on Tantra as Ground, Path and Goal' in The Journal of the Tibet Society, Volume 4, 1984
- Michael Broido, 'Padma Dkar-po on Intergration as Ground, Path and Goal' in The Journal of the Tibet Society, Volume 5, 1985
- Michael Broido, 'Padma Dkar-po on the Two Sātyas' in Journal of the International Association of Buddhist Studies 8.2, 1985
- Padma Karpo Ngawang Norbu, The Practice of the Co-Emergent Mahamudra, translated by Ven. Anzan Hoshin sensei, Ottawa: Great Matter Publications, 1991