Early Krishnaism started with the cult of the heroic Vāsudeva Krishna, which, several centuries later, was amalgamated with the cult of the divine child Bala Krishna and the Gopala traditions. While Vishnu is attested already in the Rigveda, the development of Krishnaism appears to take place via the worship of Vasudeva in the final centuries BCE. This earliest phase was established the time of Pāṇini (4th century BCE) who, in his Astadhyayi, explained the word vasudevaka as a bhakta (devotee) of Vasudeva. At that time, Vāsudeva was already considered as a demi-God, as he appears in Pāṇini's writings in conjunction with Arjuna as an object of worship, since Pāṇini explains that a vāsudevaka is a devotee (bhakta) of Vāsudeva.