Tibetan Buddhism is the body of Buddhist religious doctrine and institutions characteristic of Tibet, Mongolia, Tuva, Bhutan, Kalmykia and certain regions of the Himalayas, including northern Nepal, and India (particularly in Arunachal Pradesh, Ladakh, Dharamsala, Lahaul and Spiti district in Himachal Pradesh and Sikkim). It is the state religion of Bhutan. It is also practiced in Mongolia and parts of Russia (Kalmykia, Buryatia, and Tuva) and Northeast China. Religious texts and commentaries are contained in the Tibetan Buddhist canon such that Tibetan is a spiritual language of these areas. Tibetan Buddhism preserves the Vajrayana teachings of eighth century India.
The Tibetan diaspora has spread Tibetan Buddhism to many Western countries, where the tradition has gained popularity. Among its prominent exponents is the 14th Dalai Lama of Tibet. The number of its adherents is estimated to be between ten and twenty million.
Example via www.ramdass.org: Lama Tsongkhapa
Example via www.mindpodnetwork.com: About Lama Surya Das – Awakening Now