1. His original rôle as a local deity;
2. The extension of his power to the grade of a great 'lord' over a large district;
3. Dissociation from local origins to become the supreme lord of the lower world; and
4. The transfer of his name and powers as god of Nippur to Marduk, the god of Babylon.
The last two phases can best be set forth when we come to the period, marked by the political supremacy of the city of Babylon. It is sufficient, at this point, to have made clear his position as god of Nippur.
Nin-lil or Belit.
The consort of En-lil is Nin-Lil, the 'mistress of the lower world.' She is known also as Belit, the feminine form to Bel, i.e., the lady par excellence. She, too, had her temple at Nippur, the age of which goes back, at least, to the first dynasty of Ur. But the glory of the goddess pales by the side of her powerful lord. She is naught but a weak reflection of Bel, as in general the consorts of the gods are. Another title by which this same goddess was known is
Nin-khar-sag.[27]
which means the 'lady of the high or great mountain.' The title may have some reference to the great mountain where the gods were supposed to dwell, and which was known to Babylonians as the 'mountain of the lands.' Bel, as the chief of the gods, is more particularly associated with this mountain. Hence his temple is called the 'mountain house.' From being regarded as the inhabitant of the mountain, he comes to be identified with the mountain itself. Accordingly, he is sometimes addressed as the "great mountain,"[28] and his consort would therefore be appropriately termed 'the lady of the great mountain.' Besides the temple at Nippur, Belit, as Nin-khar-sag, had a sanctuary at Girsu, one of the quarters at Lagash (see under Nin-girsu), the earliest mention of which occurs on an inscription of Ur-Bau. The latter calls the goddess 'the mother of the gods,' which further establishes her identity with the consort of Bel. Entemena, another governor of Lagash, places his domain under the protection of Nin-khar-sag. The worship at Nippur, however, remained most prominent. The continued popularity of her cult is attested by the fortress Dur-zakar, which a later king, Samsu-iluna (c. 2200), erected in her honor.