The Northwest Palace of Ashur-nasir-pal II at Nimrud

Many of the monuments from the Northwest Palace at Nimrud and from the palace of Sennacherib at Nineveh, another one of Layard's discoveries, which arrived in the United States in the 19th century, came also by way of Rawlinson, who allowed bas-relief to be collected by American Christian missionaries resident in the Ottoman Empire. The missionaries sent them home to their respective colleges and seminaries, from Virginia to Maine (Stearns). The first reliefs to reach the United States in this manner, went to Williams College, Williamstown, Massachusetts. 

One reason why there are so many fragments outside of Nimrud today is that Layard, and the various individuals who followed him, found many of the slabs broken and thus only took pieces. Another reason is that sometimes a bas-relief was cut up by the "collector" into three, six or eight small pieces, the thickness of the slabs reduced, and then loaded on a donkey or camel to be taken away, only to be discovered that the load was still too heavy. So, a head, body fragments, or a single, small figure from a relief with more than one figure were taken, and the rest of the pieces of the slab were left behind.  This has left great lacuna along the palace walls as is seen on the images of the in situ remains.

In addition to the examples already being traded and sold in the antiquities market by the descendants of Layard's and Rawlinson's friends and relatives, several examples of bas-relief removed from Nimrud between the Layard-Rawlinson-Rassam generation and that of Max Mallowan were bought up, traded, and resold among American, European, and Asian collectors. (Often, provenience is difficult if not impossible to establish.) Some of those available in the market, with or without specific provenience, were scooped up by the British Museum during the years that Mallowan, and his successor, David Oates, were at Nimrud. This collecting was the personal interest of the British Museum's then Keeper of Western Asiatic Antiquities, Richard Barnett. Thus, the largest collection of Ashur-nasir-pal sculpture outside of Iraq is in the British Museum. Many other sculptures from the Northwest Palace were brought from Europe by American Collectors and Museums. For example, the Rockefellers made it possible for the Metropolitan Museum of Art in New York to establish what is the core collection in the United States, principally from the bas-relief still owned by the descendants of Charlotte and John Guest (Russell). The Los Angeles County Museum of Art acquired four slabs from New-Castle-on-Tyne and four fragments, part of a private collection, the Berg bequest, which were vetted in France, also reached Los Angeles.  Fragments resident in the United States for generations sometimes find their ways back to Europe and vice versa.  Two from Europe have found their way to museum collections in Japan.  Just tracking their movements can be a full-time job. 

Because there are several possible ways bas-relief had been taken from Nimrud, with or without permission, over the last 150 years, we do not know how many bas-relief fragments remain to be re-discovered by modern scholarship in private collections, museums, or simply in forgotten places. Every few years another fragment surfaces. Today we can document the whereabouts of 320 complete and fragments of bas-relief slabs in 80 museums and private collections, all originating from the Northwest Palace.