The birthplace of Śâktism as a definite sect seems to have been north-eastern India[692] and though it is said to be extending in the United Provinces, its present sphere of influence is still chiefly Bengal and Assam.[693] The population of these countries is not Aryan (though the Bengali language bears witness to the strong Aryan influence which has prevailed there) and is largely composed of immigrants from the north belonging to the Tibeto-Burman, Mon-Khmer and Shan families. These tribes remain distinct in Assam but the Bengali represents the fusion of such invaders with a Munda or Dravidian race, leavened by a little Aryan blood in the higher castes. In all this region we hear of no ancient Brahmanic settlements, no ancient centres of Vedic or even Puranic learning[694] and when Buddhism decayed no body of Brahmanic tradition such as existed in other parts of India imposed its authority on the writers of the Tantras. Even at the present day the worship of female spirits, only half acknowledged by the Brahmans, prevails among these people, and in the past the national deities of many tribes were goddesses who were propitiated with human sacrifices. Thus the Chutiyas of Sadiya used to adore a goddess, called Kesai Khati--the eater of raw flesh. The rites of these deities were originally performed by tribal priests, but as Hindu influence spread, the Brahmans gradually took charge of them without modifying their character in essentials. Popular Bengali poetry represents these goddesses as desiring worship and feeling that they are slighted: they persecute those who ignore them, but shower blessings on their worshippers, even on the obdurate who are at last compelled to do them homage. The language of mythology could not describe more clearly the endeavours of a plebeian cult to obtain recognition.[695] The Mahâbhârata contains hymns to Durgâ in which she is said to love offerings of flesh and wine,[696] but it is not likely that Śâktism or Tantrism--that is a system with special scriptures and doctrines--was prevalent before the seventh century A.D. for the Tantras are not mentioned by the Chinese pilgrims and the lexicon _Amara Kosha_ (perhaps _c_. 500 A.D.) does not recognize the word as a designation of religious books. Bâṇa (_c_. 630) gives more than once in his romances lists of sectaries but though he mentions Bhâgavatas and Pâśupatas, he does not speak of Śaktas.[697] On the other hand Tantrism infected Buddhism soon after this period. The earlier Tibetan translations of the Tantras are attributed to the ninth century. MSS. of the Kubjikâmata and other Tantras are said to date from the ninth and even from the seventh century and tradition represents Sankarâcârya as having contests with Śâktas.[698] But many Tantras were written in the fifteenth century and even later, for the Yogini Tantra alludes to the Koch king Bishwa Singh (1515-1540) and the Meru Tantra mentions London and the English.