Vāsudeva

Vāsudeva (; Sanskrit: वासुदेव [ʋɑːsudéːʋɐ]), also known as Vāsudeva-Krishna (Vāsudeva-Kṛṣṇa) or Krishna-Vāsudeva, was a deified Vrishni hero of the Vrishni-clan, and may well have been a historical ruler in the region of Mathura. The movement of Vāsudeva was one of the major independent religious movements alongside those of Narayana, Shri and Lakshmi, which later coalesced to form Vaishnavism.

His religious following developed after the Vedic period, and was the first expression of what was to become Vaishnavism. It was one of the earliest forms of personal deity worship in India, and is attested from around the 4th century BCE, when he was already considered as a deity, as he appears in Pāṇini's writings in conjunction with Arjuna as an object of worship. By the end of the 2nd century BCE, Vāsudeva was considered as Devadeva, the "God of Gods", the Supreme Deity, whose emblem was the mythical bird Garuda, as known from the Heliodorus pillar inscription.

After the movement of Vāsudeva had been established, the tribe of the Vrishnis fused with the tribe of the Yadavas, who had their own hero-god named Krishna. Vāsudeva was fused with Krishna, becoming Vāsudeva-Krishna (Vāsudeva-Kṛṣṇa), or Krishna-Vāsudeva. It is unknown at what point of time precisely Vāsudeva came to be associated with "Krishna," but the association between the names "Vāsudeva" and "Krishna" starts to appear with the Mahabharata and the Harivamsa, both completed in the 3rd century CE, where Krishna is called "Vāsudeva," a patronymic referring to his father Vasudeva Anakadundubhi.

The fused religious movement of Vāsudeva-Krishna became a major component of the amalgamated worship of Krishna, who was incorporated into Vaishnavism as the 8th incarnation of Vishnu. According to the Vaishnava doctrine of the avatars, Vishnu takes various forms to rescue the world, with Vāsudeva-Krishna understood as one of the most popular ones.