The first significant addition of Mesopotamian objects was from the collection of Claudius James Rich in 1825. The collection was later dramatically enlarged by the excavations of A. H. Layard at the Assyrian sites of Nimrud and Nineveh between 1845 and 1851. At Nimrud, Layard discovered the North-West Palace of Ashurnasirpal II, as well as three other palaces and various temples. He later uncovered the Palace of Sennacherib at Nineveh with 'no less than seventy-one halls'. As a result, a large numbers of Lamassu's, bas-reliefs, stelae, including the Black Obelisk of Shalmaneser III, were brought to the British Museum.