We do not find Sin, the Babylonian moon-god, extensively worshipped in Assyria. Assur-nazir-pal founded a temple to him in Calah, and Sargon raised several sanctuaries to him beyond the Assyrian frontier. It is as a war-god chiefly that we find him depicted in the northern kingdom--why, it would be difficult to say, unless, indeed, it was that the Assyrians turned practically all the deities they borrowed from other peoples into war-gods. So far as is known, no lunar deity in any other pantheon possesses a military significance. Several are not without fear-inspiring attributes, but these are caused chiefly by the manner in which the moon is regarded among primitive peoples as a bringer of plague and blight. But we find Sin in Assyria freed from all the astrological significances which he had for the Babylonians. At the same time he is regarded as a god of wisdom and a framer of decisions, in these respects equating very fully with the Egyptian Thoth. Assur-bani-pal alludes to Sin as 'the first-born son of Bel,' just as he is alluded to in Babylonian texts, thus affording us a clue to the direct Babylonian origin of Sin.
It is strange that although we know that Nusku had been a Babylonian god from early times, and had figured in the pantheon of Khammurabi, it is not until Assyrian times that we gain any very definite information regarding him. The symbols used in his name are a sceptre and a stylus, and he is called by Shalmaneser I 'The Bearer of the Brilliant Sceptre.' This circumstance associates him closely with Nabu, to designate whom the same symbols are employed. It is difficult, however, to believe that the two are one, as some writers appear to think, for Nusku is certainly a solar deity, while Nabu appears to have originally been a water-god. There are, however, not wanting cases where the same deity has evinced both solar and aqueous characteristics, and these are to be found notably among the gods of American races. Thus among the Maya of Central America the god Kukulcan is depicted with both solar and aqueous attributes, and similar instances could be drawn from lesser-known mythologies. Nusku and Nabu are, however, probably connected in some way, but exactly in what manner is obscure. In Babylonian times Nusku had become amalgamated with Gibil, the god of fire, which perhaps accounts for his virtual effacement in the southern kingdom. In Assyria we find him alluded to as the messenger of Bel-Merodach, and Assur-bani-pal addresses him as 'the highly honoured messenger of the gods.' The Assyrians do not seem to have identified him in any way with Gibil, the fire-god.