Karmapa in the context of "Karma Kagyu"

The Kagyu school, also transliterated as Kagyü, or Kagyud (Tibetan: བཀའ་བརྒྱུད།, Wylie: bka' brgyud), which translates to "Oral Lineage" or "Whispered Transmission" school, is one of the main schools (chos lugs) of Tibetan Buddhism. The Kagyu lineages trace themselves back to the 11th century Indian Mahasiddhas Naropa, Maitripa and the yogini Niguma, via their student Marpa Lotsawa (1012–1097), who brought their teachings to Tibet. Marpa's student Milarepa was also an influential poet and teacher.

The Tibetan Kagyu tradition gave rise to a large number of independent sub-schools and lineages. The principal Kagyu lineages existing today as independent schools are those which stem from Milarepa's disciple, Gampopa (1079–1153), a monk who merged the Kagyu lineage with the Kadam tradition. The Kagyu schools which survive as independent institutions are mainly the Karma Kagyu, Drikung Kagyu, Drukpa Lineage and the Taklung Kagyu. The Karma Kagyu school is the largest of the sub-schools, and is headed by the Karmapa. Other lineages of Kagyu teachings, such as the Shangpa Kagyu, are preserved in other schools.

A tulku (Tibetan: སྤྲུལ་སྐུ་, Wylie: sprul sku, ZWPY: Zhügu, also tülku, trulku) is an individual recognized as the reincarnation of a previous spiritual master (lama), and expected to be reincarnated, in turn, after death. The tulku is a distinctive and significant aspect of Tibetan Buddhism, embodying the concept of enlightened beings taking corporeal forms to continue the lineage of specific teachings. The term "tulku" is a loanword from Tibetan སྤྲུལ་སྐུ ("sprul sku"), which originally referred to an emperor or ruler taking human form on Earth, signifying a divine incarnation. Over time, it evolved within Tibetan Buddhism to denote the corporeal existence of certain highly accomplished Buddhist masters whose purpose was to ensure the preservation and transmission of a particular lineage.

The tulku system originated in Tibet, particularly associated with the recognition of the second Karmapa in the 13th century. Since then, numerous tulku lineages have been established, with each tulku having a distinctive role in preserving and propagating specific teachings. Other high-profile examples of tulkus include the Dalai Lamas, the Panchen Lamas, the Samding Dorje Phagmos, Khyentses, the Zhabdrung Rinpoches, and the Kongtruls.