and achieve a degree of political ascendancy.  It does not follow, however, that the peasant class was greatly affected by periodic revolutions of this kind, which brought little more to them than a change of rulers.  The needs of the country necessitated the continuance of agricultural methods and the rigid observance of existing land laws; indeed, these constituted the basis of Sumerian prosperity.  Conquerors have ever sought reward not merely in spoil, but also the services of the conquered.  In northern Babylonia the invaders apparently found it necessary to conciliate and secure the continued allegiance of the tillers of the soil.  Law and religion being closely associated, they had to adapt their gods to suit the requirements of existing social and political organizations.  A deity of pastoral nomads had to receive attributes which would give him an agricultural significance; one of rural character had to be changed to respond to the various calls of city life.  Besides, local gods could not be ignored on account of their popularity.  As a result, imported beliefs and religious customs must have been fused and absorbed according to their bearing on modes of life in various localities.  It is probable that the complex character of certain deities was due to the process of adjustment to which they were subjected in new environments.

The petty kingdoms of Sumeria appear to have been tribal in origin.  Each city was presided over by a deity who was the nominal owner of the surrounding arable land, farms were rented or purchased from the priesthood, and pasture was held in common.  As in Egypt, where we find, for instance, the artisan god Ptah supreme at Memphis, the sun god Ra at Heliopolis, and the cat goddess Bast at Bubastis, the various local Sumerian and Akkadian deities had distinctive characteristics, and similarly showed a tendency to absorb the attributes of their rivals.  The chief deity of a state was the central figure in a pantheon, which had its political aspect and influenced the growth of local theology.  Cities, however, did not, as a rule, bear the names of deities, which suggests that several were founded when Sumerian religion was in its early animistic stages, and gods and goddesses were not sharply defined from the various spirit groups.

A distinctive and characteristic Sumerian god was Ea, who was supreme at the ancient sea-deserted port of Eridu.  He is identified with the Oannes of Berosus,[31] who referred to the deity as “a creature endowed with reason, with a body like that of a fish, with feet below like those of a man, with a fish’s tail”.  This description recalls the familiar figures of Egyptian gods and priests attired in the skins of the sacred animals from whom their powers were derived, and the fairy lore about swan maids and men, and the seals and other animals who could divest themselves of their “skin coverings” and appear in human shape.  Originally Ea may have been a sacred fish.  The Indian creative