According to the celebrated Hindu scriptures (the Bhagavad-gita, Bhagavata Purana and the Brahma-samhita), Krishna is the "bhagavan-svayam": the ultimate, highest and original manifestation of the Godhead. He is the source of all of the incarnations of
Vishnu; in fact,
Vishnu is a plenary expansion of Krishna. This
definition is corroborated by the scriptures Mahabharata, Harivamsa, Padma Purana and the Gita-govinda, et al.