They were legendary warriors, and martial discipline or "action meditation" is their path to spiritual enlightenment.
The Dalai Lama leads one of the four schools, or denominations within Tibetan Buddhism. The 23-year-old Karmapa Lama leads another. His supporters believe he may one day succeed the older man as Buddhism's leading international voice.
Read more of the Religion & Ethics NewsWeekly interview with Tu Weiming, professor of Chinese history and philosophy and Confucian studies at Harvard University.