Adar, or Ninep, or Uras—for his name has been read in these various fashions, and the true reading still remains unknown¹—played a conspicuous part in Babylonian, and more especially Assyrian theology.  He was regarded as emphatically the warrior and champion of the gods, and as such was naturally a favourite object of worship amongst a nation of warriors like the Assyrians.  Indeed, it may be suspected that the extent to which the name of the older Bel was reverenced in Assyria was in some measure due to the favour in which his son Adar was held.  In the inscriptions of Nineveh, the title of "hero-god" (masu) is applied to him with peculiar frequency; this was the characteristic upon which the Assyrian kings more particularly loved to dwell.  In Babylonia, on the other hand, Adar was by no means so favourite a divinity.  Here it was the milder and less warlike Merodach that took his place.  The arts of peace, rather than those of war, found favour among the Semitic population of the southern kingdom.
    ¹ The only form out of these three which is monumentally established is Uras.  Uras is given as the pronunciation of the second ideograph in the name of the god (W.A.I. iii. 70, 203—207, ii. 54, 34); and in W.A.I. ii. 57, 31, Uras is expressly stated to be the name of NIN-IP, as "god of light" (uddanê, see ii. 62, 36, where there is a play on the Assyrian baru, "fat," and baru, "to reveal").  From uras the Assyrians borrowed their urasu, "a mourning veil" (v. 28, 60).  IP and NIN-IP were two primaeval deities who in Accadian cosmology represented the male and female principles, but the genderless character of the Accadian nin, "lord" or "lady," caused the Semites to change NIN-IP into a god and identify him with IP,t hat is, "Anu who listens to prayer" (ii. 54, 35).  As u signified "lord" in Accadian, it would seem that they further identified the first syllable of U-ras with the nia of Nin-Uras.  Hence "the Assyrian king," Horus of Pliny (N.H. xxx. 51, cp. xxxvii. 52), who discovered a cure for drunkenness, as well as the Thouras of Kedronos (Hist. 56, 16, cp. Suidas and the Paschal Chron. p. 68), who is called the Assyrian Ares and made the son of Zamas or Samas.  The reading Adar is derived from the Biblical Adrammelech, but it is quite certain that it is false, and I have retained it in the text only on account of its employment by other Assyriologists.
(Lectures on the Origin and Growth of Religion as Illustrated by the Religion of the Ancient Babylonians, Sayce, 1897).