The Cambridge History of India, Vol. I: Ancient India v1.c17.134

v1.c17.134

As might be expected, the Brāhmaṇa period presents us with a stage intermediate between the rules of the Sūtras and the laxity of the Rigveda. The rule as to marriage within the circle of the cognates and agnates seems, by the time of the Çatapatha Brāhmaṇa, to have extended only to the prohibition of marriage with relations of the third or, according to others, of the fourth degree. Similarly in the Brāhmaṇas, while we have no reason to doubt that priesthood and nobility were hereditary, these castes seem to have been free to intermarry with the lower castes including the Çūdra, as the cases of Vatsa and Kavasha cited above indicate. The marriage of a Brāhman with the daughter of a king is attested by the case of Sukanyā, the daughter of Çaryāta, who married the seer, Chyavana.