The palace reliefs were fixed to the walls of royal palaces forming continuous strips along the walls of large halls. The style apparently began after about 879 BC, when Ashurnasirpal II moved the capital to Nimrud, near modern Mosul in northern Iraq. Thereafter, new royal palaces, of which there was typically one per reign, were extensively decorated in this way for the roughly 250 years until the end of the Assyrian Empire. There was subtle stylistic development, but a very large degree of continuity in subjects and treatment.
Compositions are arranged on slabs, or orthostats, typically about 7 feet high, using between one and three horizontal registers of images, with scenes generally reading from left to right. The sculptures are often accompanied with inscriptions in cuneiform script, explaining the action or giving the name and extravagant titles of the king. Heads and legs are shown in profile, but torsos in a front or three-quarters view, as in earlier Mesopotamian art. Eyes are also largely shown frontally. Some panels show only a few figures at close to life-size, such scenes usually including the king and other courtiers, but depictions of military campaigns include dozens of small figures, as well as many animals and attempts at showing landscape settings.
Campaigns focus on the progress of the army, including the fording of rivers, and usually culminate in the siege of a city, followed by the surrender and paying of tribute, and the return of the army home. A full and characteristic set shows the campaign leading up to the siege of Lachish in 701; it is the "finest" from the reign of Sennacherib, from his palace at Nineveh and now in the British Museum. Ernst Gombrich observed that none of the many casualties ever come from the Assyrian side. Another famous sequence there shows the Lion Hunt of Ashurbanipal, in fact the staged and ritualized killing by King Ashurbanipal of lions already captured and released into an arena, from the North Palace at Nineveh. The realism of the lions has always been praised, and the scenes are often regarded as "the supreme masterpieces of Assyrian art", although the pathos modern viewers tend to feel was perhaps not part of the Assyrian response.
There are many reliefs of minor supernatural beings, called by such terms as "winged genie", but the major Assyrian deities are only represented by symbols. The "genies" often perform a gesture of purification, fertilization or blessing with a bucket and cone; the meaning of this remains unclear. Especially on larger figures, details and patterns on areas such as costumes, hair and beards, tree trunks and leaves, and the like are very meticulously carved. More important figures are often shown larger than others, and in landscapes more distant elements are shown higher up, but not smaller than, those in the foreground, though some scenes have been interpreted as using scale to indicate distance. Other scenes seem to repeat a figure in a succession of different moments, performing the same action, most famously a charging lion. But these were apparently experiments that remain unusual.
The king is often shown in narrative scenes, and also as a large standing figure in a few prominent places, generally attended by winged genies. A composition repeated twice in what is traditionally called the "throne-room" (though perhaps it was not) of Ashurbanipal's palace at Nimrud shows a "Sacred Tree" or "Tree of Life" flanked by two figures of the king, with winged genies using the bucket and cone behind him. Above the tree one of the major gods, perhaps Ashur the chief god, leans out of a winged disc, relatively small in scale. Such scenes are shown elsewhere on the robe of the king, no doubt reflecting embroidery on the real costumes, and the major gods are normally shown in discs or purely as symbols hovering in the air. Elsewhere the tree is often attended to by genies.
Women are relatively rarely shown, and then usually as prisoners or refugees; an exception is a "picnic" scene showing Ashurbanipal with his queen. The many beardless royal attendants can probably be assumed to be eunuchs, who ran much of the administration of the empire, unless they also have the shaved heads and very tall hats of priests. Kings are often accompanied by several courtiers, the closest to the king probably often being the appointed heir, who was not necessarily the oldest son.
The enormous scales of the palace schemes allowed narratives to be shown at an unprecedentedly expansive pace, making the sequence of events clear and allowing richly detailed depictions of the activities of large numbers of figures, not to be paralleled until the Roman narrative column reliefs of the Column of Trajan and Column of Marcus Aurelius.
Pair of lamassu
, with the five legs of the left one showing.
Lamassu were protective minor deities or spirits, the Assyrian version of the "human-headed bull" figure that had long figured in Mesopotamian mythology and art. Lamassu have wings, a male human head with the elaborate headgear of a divinity, and the elaborately-braided hair and beards shared with royalty. The body is that of either a bull or a lion, the form of the feet being the main difference. Prominent pairs of lamassu were typically placed at entrances in palaces, facing the street and also internal courtyards. They were "double-aspect" figures on corners, in high relief, a type earlier found in Hittite art. From the front they appear to stand, and from the side, walk, and in earlier versions have five legs, as is apparent when viewed obliquely. Lamassu do not generally appear as large figures in the low-relief schemes running round palace rooms, where winged genie figures are common, but they sometimes appear within narrative reliefs, apparently protecting the Assyrians.
The colossal entrance way figures were often followed by a hero grasping a wriggling lion, also colossal and in high relief; these and some genies beside lamassu are generally the only other types of high relief in Assyrian sculpture. The heroes continue the Master of Animals tradition in Mesopotamian art, and may represent Enkidu, a central figure in the ancient Mesopotamian Epic of Gilgamesh. In the palace of Sargon II at Khorsabad, a group of at least seven lamassu and two such heroes with lions surrounded the entrance to the "throne room", "a concentration of figures which produced an overwhelming impression of power". The arrangement was repeated in Sennacherib's palace at Nineveh, with a total of ten lamassu. Other accompanying figures for colossal lamassu are winged genies with the bucket and cone, thought to be the equipment for a protective or purifying ritual.
Lamassu also appear on cylinder seals. Several examples left in situ in northern Iraq have been destroyed in the 2010s by ISIL when they occupied the area. Colossal lamassu also guarded the start of the large canals built by the Assyrian kings. In the case of temples, pairs of colossal lions guarding the entrances have been found.
Relief fragments from Nimrud, showing the depth of the slabs (probably sawn down in excavation) and scale. The main head belongs to a court eunuch.
There are outcrops of the "Mosul marble" gypsum rock normally used at several places in the Assyrian realm, though not especially close to the capitals. The rock is very soft and slightly soluble in water, and exposed faces degraded, and needed to be cut into before usable stone was reached. There are reliefs showing quarrying for Sennacherib's new palace at Nineveh, though concentrating on the production of large lamassu. Blocks were extracted, using prisoners of war, and sawed into slabs with long iron saws. This may have happened at the palace site, which is certainly where the carving of orthostats was done, after the slabs had been fixed into place as a facing to a mud-brick wall, using lead dowels and clamps, with the bottoms resting on a bed of bitumen. For some reliefs an "attractive fossiliferous limestone" is used, as in several rooms in the South-West Palace at Nineveh. In contrast to the orthostats, the lamassu were carved, or at least partly so, at the quarry, no doubt to reduce their enormous weight.
The alabaster stone is soft but not brittle, and very suitable for detailed carving with early Iron Age tools. There can be considerable differences in style, and quality, between adjacent panels, suggesting that different master carvers were allocated these. Probably the master drew or incised the design on the slab before a team of carvers laboriously cut away the background areas and finished carving the figures. Scribes then set out any inscriptions for cutters to follow, after which the slab was polished smooth, and any paint added. Scribes are shown directing carvers in another relief (on the Balawat Gates) showing the creation of a rock relief; presumably they ensured that the depiction of royal and religious aspects of the subjects was as it should be.
The reliefs only covered the lower parts of the walls of rooms in the palaces, and higher areas were often painted, at least in patterns, and at least sometimes with other figures. Brightly coloured carpets on the floor completed what was probably a striking decor, largely in primary colours. None of these have survived, but we have some door-sills carved with repeated geometric motifs, presumed to imitate the carpets.
After the palaces were abandoned and lost their wooden roofs, the unbaked mud-brick walls gradually collapsed, covering the space in front of the reliefs, and largely protecting them from further damage from the weather. Relatively few traces of paint remain, and these are often on heads and faces – hair and beards were black, and at least the whites of eyes white. Possibly metal leaf was used on some elements, such as small scenes shown decorating textiles. Julian Reade concludes that "It is nonetheless puzzling that more traces of painting [on sculpture] have not been recorded".