The problem was further compounded by the fact that each god had his own
particular sphere of activity. The sun god Shamash was in charge of justice while the goddess Ishtar embraced both love and war. But inevitably there was considerable overlapping
among the pantheons of the many cities. The theologians made gargantuan
efforts to systematize the hierarchy and functions of the gods. They drew up long
lists of the numerous god names and, in a parallel column, equated the numerous
lesser gods with one of the greater and better-known deities. These syncretic
lists became a literary tradition and were passed on from century to century with
revisions and additions.
Also see: The Babylonian Pantheon of Gods