As most of the early peoples were nomadic, or periodically nomadic, there must have been in localities a good deal of interracial and intertribal fusion, with the result that intermediate varieties were produced. It follows that the intellectual life of the mingling peoples would be strongly influenced by admixture as well as by contact with great civilizations. It now remains for us to deal with the Aryan problem in India. Dr. Haddon considers that the invading Aryans were “perhaps associated with Turki tribes” when they settled in the Punjab.[14] Prior to this racial movement, the Kassites, whose origin is obscure, assisted by bands of Aryans, overthrew the Hammurabi dynasty in Babylon and established the Kassite dynasty between 2000 B.C. and 1700 B.C. At this period the domesticated horse was introduced, and its Babylonian name, “the ass of the East”, is an indication whence it came. Another Aryan invasion farther west is marked by the establishment of the Mitanni kingdom between the area controlled by the Assyrians and the Hittites. Its kings had names which are clearly Aryan. These included Saushatar, Artatatama, Sutarna, and Tushratta. The latter was the correspondent in the Tel-el-Amarna letters of his kinsmen the Egyptian Pharaohs, Amenhotep the Magnificent, and the famous Akhenaton. The two royal houses had intermarried after the wars of Thothmes III. It is impossible to fix the date of the rise of the Mitanni power, which held sway for a period over Assyria, but we know that it existed in 1500 B.C. The horse was introduced into Egypt before 1580 B.C. [14] _The Wanderings of Peoples_, A. C. Haddon, p. 21. It is generally believed that the Aryans were the tamers of the horse which revolutionized warfare in ancient days, and caused great empires to be overthrown and new empires to be formed. When the Aryans entered India they had chariots and swift steeds. There is no general agreement as to the date of settlement in the Punjab. Some authorities favour 2000 B.C., others 1700 B.C.; Professor Macdonell still adheres to 1200 B.C.[15] It is possible that the infusion was at first a gradual one, and that it was propelled by successive folk-waves. The period from the earliest migrations until about 800 or 700 B.C. is usually referred to as the Vedic Age, during which the Vedas, or more particularly the invocatory hymns to the deities, were composed and compiled. At the close of this Age the area of Aryan control had extended eastward as far as the upper reaches of the Jumna and Ganges rivers. A number of tribal states or communities are referred to in the hymns. [15] _Vedic Index of Names and Subjects_ (1912), p. viii. It is of importance to note that the social and religious organization of the Vedic Aryans was based upon the principle of “father right”, as contrasted with the principle of “mother right”, recognized by representative communities of the Brown race.