HIRA, the capital of an Arabian kingdom, founded in the 2nd century A.D., on the western edge of Irak, was situated at 32 N., 44 20' E., about 4 m. S.E. of modern Nejef, by the Sa'ade canal, on the shore of the Bahr Nejef or Assyrium Stagnum. Its kings governed the western shore of the lower Euphrates and of the Persian Gulf, their kingdom extending inland to the confines of the Nejd. This Lakhmid kingdom was more or less dependent, during the four centuries of its existence, on the Sassanian empire, to which it formed a sort of buffer state towards Arabia. After the battle of Kadesiya and the founding of Kufa by the Arabs, Hira lost its importance and fell into decay. The ruin mounds covering the ancient site, while extensive, are insignificant in appearance and give no indications of the existence of important buildings.
Note - this article incorporates content from Encyclopaedia Britannica, Eleventh Edition, (1910-1911)