Ramanuja's doctrine, which is especially directed against the Linga-worship, is essentially based on the tenets of an old Vaishnava sect, the Bhagavatas or Pancharatras, who worshipped the Supreme Being under the name of Vasudeva (subsequently identified with Krishna, as the son of Vasudeva, who indeed is credited by some scholars with the foundation of that monotheistic creed).
The theory of Avataras which makes the deity - also variously called Narayana, Purushottama, or Vasudeva - periodically assume some material form in order to rescue the world from some great calamity, is fully developed; the ten universally recognized" descents "being enumerated in the larger poem.
Thus (though earlier Indian and Bactrian coins do not show it) it is found with the gods on some of the coins of the Indian kings Kanishka, Huvishka and Vasudeva, 58 B.C. to A.D.