Karma Kagyu
Karma Kagyu (), or Kamtsang Kagyu (), is a widely practiced and probably the second-largest lineage within the Kagyu school, one of the four major schools of Tibetan Buddhism. The lineage has long-standing monasteries in Tibet, China, Russia, Mongolia, India, Nepal and Bhutan, with current centres in over 60 countries. The spiritual head of the Karma Kagyu is the "Gyalwa Karmapa"; the 2nd through 10th Karmapas were principal spiritual advisors to successive emperors of China. The Karma Kagyu are sometimes called the "Black Hat" lamas, in reference to the Black Crown worn by the Karmapa.