In Hinduism, an encyclopaedic collection of myth, legend, and genealogy. A Purana traditionally treats five subjects: primary creation of the universe, secondary creation after periodic annihilation, genealogy of gods and saints, grand epochs, and histories of the royal dynasties. Written in narrative couplets, the Puranas date from c. 400 to c. 1000. The 18 principal surviving Puranas are grouped according to whether they exalt Vishnu, Shiva, or Brahma. Most popular is the Bhagavata Purana, which treats the early life of Krishna.