The Dalai Lama is a high lama in the Gelug or “Yellow Hat” school of Tibetan Buddhism, founded by Tsongkhapa (1357–1419). The name is a combination of the Mongolian word dalai meaning “Ocean” and the Tibetan word བླ་མ་ bla-ma (with a silent “b”) meaning “guru, teacher”. According to Tibetan Buddhist doctrine, the Dalai Lama is the rebirth in a line of tulkus who are metaphorically considered to be manifestations of the bodhisattva of compassion, Avalokiteśvara.