Black Obelisk, Assyrian monument of King Shalmaneser III (reigned 858–824 bc). The most complete Assyrian obelisk yet discovered, it is decorated with cuneiform inscriptions and reliefs recording military campaigns and other triumphs, including payment of tribute by King Jehu of Israel (reigned 842–815). The 6-foot (1.8-metre) black basalt piece was discovered in 1845 at ancient Kalhu (or Kalakh; biblical Calah; modern Nimrūd), south of Mosul, Iraq, by Austen Henry Layard and is now in the British Museum.