Previous reports on the current series of campaigns at Nimrud have from time to time referred to discoveries of post-Assyrian material, indicating an impoverished, and probably intermittent, occupation of the site during the last six centuries B.C. Analysis and identification of the finds has hitherto been impeded by two obstacles, the lack of dated comparative material from Northern Mesopotamia, and the difficulty of obtaining an undisturbed stratigraphic sequence on a mound so thoroughly ransacked by earlier excavators, who were interested only in the Assyrian levels. During the seasons 1949–53, when work was concentrated on the northern and central parts of the mound, occasional objects were found without an informative context, but it was not until we came to deal with the sites of the Burnt Palace and Nabu Temple in the southeast quarter, in 1955 and 1956, that we found the evidence better preserved, with isolated groups of material in situ. A reliable sequence was still lacking, and to fill this gap in 1957 we made a sounding on the high south-east corner, on a small plateau which showed little superficial sign of previous disturbance. Our aim was two-fold: to obtain a conspectus of the post-Assyrian levels, and to re-examine the Assyrian building beneath, the existence of which was briefly reported by Layard and Loftus. The quantity of debris, more than seven metres in depth, above the Assyrian level made it impossible to attempt any large-scale clearance, and we confined ourselves to three new trenches (O, P and R on the plan, Pl. XV) cut from north to south across the patch of virgin ground, and at the same time reopened Layard's large pit a short distance to the west. In trenches O and P we made a methodical, stratigraphic examination of six post-Assyrian levels before reaching a zone of barren debris, largely fallen mud brick, which overlay the Assyrian walls; our resources did not permit us to carry the excavation down to the Assyrian floors. In Trench R, begun late in the season, we confirmed the sequence of trenches O and P down to the fifth level. In Layard's excavation to the west, exposing the throne-room complex of the AB Palace, the post-Assyrian deposits had been extensively disturbed, but we were able to reconstruct them in part from the sides of his original cut and recovered some interesting groups of pottery and grave goods which can be related with fair certainly to the main sequence.