Vishnu would much later become prominent in this construct, so that by the middle of the 5th century CE, during the Gupta period, the term Vaishnava would replace the term Bhagavata to describe the followers of this cult, and Vishnu would now be more popular than Vāsudeva. Bhagavatism would introduce the concept of the chatur-vyuhas, in which the four earthly emanations of Narayana were considered to be Vasudeva (Krishna) as the creator, Sankarsana (Balarama) as the preserver, Pradyumna as the destroyer, and Aniruddha as the aspect of intellect. The concept of vyuhas would later be supplanted by the concept of avataras, indicating the transformation of Bhagavatism into Vaishnavism. Some relate absorption by Brahmanism to be the characteristic of the second stage of the development of the Bhagavata tradition. It is believed that at this stage Krishna-Vāsudeva was identified with the deity of Vishnu, that according to some belonged to the pantheon of Brahmanism. Rulers onwards from Chandragupta II, Vikramaditya were known as parama Bhagavatas, or Bhagavata Vaishnavas. The Bhagavata Purana entails the fully developed tenets and philosophy of the Bhagavata cult where Krishna gets fused with Vasudeva and transcends Vedic Vishnu and cosmic Hari to be turned into the ultimate object of bhakti. Adoption in Tamilakam With the fall of the Guptas, Bhagavatism had lost its pre-eminence in the north, with Vardhana sovereigns such as Harsha adhering to non-Bhagavata creeds. Though the Bhagavata religion still flourished in the north, its stronghold was now not the valley of the Ganges or Central India, but the Tamil country. There, the faith flourished under the strong impetus given by the Alvars, “who by their Tamil songs inculcated Bhakti and Krishna-worship mainly.” Bhagavatism had penetrated into the Deccan at least as early as the first century BCE. The Silappadikaram and the other ancient Tamil poems refer to temples dedicated to Krishna and his brother at Madura, Kaviripaddinam, and other cities. The wide prevalence of Bhagavatism in the far south is also testified to by the Bhagavata Purana which says that in the Kali Age, devoted worshippers of Narayana, though rare in some places, are to be found in large numbers in the Dravida country watered by the rivers Tamraparnl, Kritamala, the sacred Kaveri, and the great stream (Periyar) flowing to the west. Yamunacharya, who laid the tenets of the Vishishtadvaita philosophy, has his works described as "a somwhat modified and methodical form of the