The Adi Parva describes the creation of the cosmos and the legendary history of the kings of the Solar and Lunar dynasties leading up to the birth of Krishna. Vishnu Parva recounts the history of Krishna up to the events prior to the "Mahabharata". Bhavishya Parva, the third book, includes two alternate creation theories, hymns to Shiva and Vishnu and provides a description of the Kali Yuga. While the "Harivansha" has been regarded as an important source of information on the origin of Vishnu's incarnation Krishna, there has been speculation as to whether this text was derived from an earlier text and what its relationship is to the Brahma Purana, another text that deals with the origins of Krishna.