Devout Hindus believe that whenever evil is on the ascendant, Vishnu
descends on earth to uphold righteousness and to destroy evil. The tales of these descents or avatars told in various Puranas have contributed in no small measure to make Vishnu the most popular of Hindu deities. His worshippers are called Vaishnavas. The Bhagawat Purana, from which the tales in the first title are adapted, abounds with narratives of Vishnu's benevolent acts. Narada is the most popular of Vishnu's devotees. The three tales about Narada in the second title are based on the Shiva Purana and some popular legends. The story of Prahlad has been retold from the Bhagawat Purana and the Vishnu Purana. The Churning of the Ocean' is a popular tale found in the Puranas as well as in the two epics. There is some difference, however, regarding the number of the articles which appeared from the ocean of milk. The Ramayana, the Mahabharata
and the Padma Purana specify the number as nine, while the Bhagwat Purana specifies it as ten, the Vayu Purana as twelve and the Matsya Purana as fourteen. Similarly, there are slight differences regarding the role of the asura, Rahu. Our version is derived mainly from the Bhagawat Purana and the Mahabharata. The story of Dhruva is based on the Bhagwat Purana and ' Ashtavakra' is based on the Mahabharata.