Buddhism: TopicReligion and philosophy founded in India c.525 B.C. by Siddhartha Gautama, called the Buddha. There are over 300 million Buddhists worldwide. One of the great world religions, it is divided into two main schools: the Theravada or Hinayana in Sri Lanka and SE Asia, and the Mahayana in China, Mongolia, Korea, and Japan. A third school, the Vajrayana, has a long tradition in Tibet and Japan.