Holman Bible Dictionary 
Cyclopedia of Biblical, Theological and Ecclesiastical Literature 
one of the chief deities of the Assyrians and Babylonians alike, although she was generically one of the deities of the second rank. She was the daughter of the moon-god Sin, and was identified by the Chaldaeans with the planet Venus. She was essentially a warlike goddess, and was called the "Goddess of Battles and of Victories," in which attribute she was often represented as giving a bow to the Assyrian king in token of his victories over his foes. She was also, as, the goddess of productive nature, the keeper of all the treasures of the earth, and hence was figured as Allat, the "Queen of the Spear or Divining-rod." In another form of the same principle she was the goddess of sensual indulgence. She was the special protectress of Erech, and in her character of Anna, or Nana, of Nineveh, while she was distinguished also at Arbela, another great seat of her worship, as Ishtar of Arbela. Her offices, names, and attributes were very various, and there appears to have been two Ishtars, mother and daughter, one the great nature goddess, the other the heroine of one of the mythical legends, called the "Descent of Ishtar into Hades." There is a considerable amount of confusion yet remaining to be cleared away with regard to the relations of Ishtar to Davcina, Bilit, Ashtaroth, and Izdubar; but generally the mythologies agree in making her the goddess most brought into contact with men and the under world.