Dalai Lama, dah LY LAH muh, is the leader of the Yellow Hat (also known as Gelugpa), the chief Buddhist sect of Tibet. The title means "teacher whose wisdom is great as the ocean." The Dalai Lama served as the political and religious ruler of Tibet from the reign of the fifth Dalai Lama in the 1600's to 1959. In that year, the Dalai Lama went into exile in response to China's control of Tibet.