Immediately after the death of the Buddha, differences arose among his followers as to the interpretation of the Master's teachings. After the second council held at Vaishali, two great schools, the 'Sthaviravadins' (Hinayana) and 'Mahasanghikas' came into being. Hinayana is also known as Theravada (Doctrine of elders) because it's followers claimed that their views had the support of the Buddha's immediate followers. According to them Buddha was the supreme teacher. By the time of Ashoka, there were eighteen different schools. Ashoka convoked the third council to stem the tide. In the ultimate, Mahasanghikas paved way for the emergence of 'Mahayana' (large Vehicle) in the first century AD. The Mahayanists believed that all things were of non-essential and indefinable in character, and void at bottom. They looked upon Buddha not merely as a teacher but as a saviour, a Bodhisattva (Essence of Wisdom). The Mahayanists emphasis on the Bodhisattva theory, led to the emergence of another school called 'Yogacara'. In this school, not only imaginary beings but exponents or leaders of various sects were also defined as Bodhisattvas. As a result of inter-mingling of Buddhistic and Brahmanical speculations the Yogacara school paved way for' Vajrayana' or Tantric Buddhism. Today, there are three major types of Buddhism; Theravada, Mahayana and Vajrayana.