In one of the most memorable scenes in “The Epic of Gilgamesh”, the world’s oldest epic, the eponymous hero confronts Humbaba, a monster who guards the Cedar Forest, the realm of the gods at the edge of the mortal world. Humbaba is described as “a terror to human beings”, with the face of a lion, thorny scales for skin, and a snake for a tail. Gilgamesh slays Humbaba and wins eternal fame. His victory symbolises the triumph of order over primordial chaos, and the establishment of civilisation.

The reason that we know as much as we do about the exploits of Gilgamesh is largely thanks to Ashurbanipal, the last great king of the Assyrians. This self-styled “king of the world”, who ruled from 669 to 631 BC , is the subject of an exhibition at the British Museum. It uses carved stone panels and sculptures, mainly from the British Museum’s collection, to explore life in Ashurbanipal’s palace at Nineveh, in what is now Mosul in Iraq, and narrate the stories of his many military conquests. The centrepiece of the exhibition is a vast cabinet full of clay tablets, inscribed with ancient cuneiform writing, that belonged to Ashurbanipal’s library – the first systematically organised one in the ancient world. “The Epic of Gilgamesh” was rediscovered in 1853 during excavations at Nineveh.

Like Gilgamesh, Ashurbanipal’s duty as king was to create order from chaos – but unlike previous kings, Ashurbanipal saw scholarship as a way to strengthen his grip on power. Many of the texts in his library fell into the category of “omen literature”, by which scholars attempted to divine and to forestall the perils the future held. Ashurbanipal needed any help he could get, for the ancient Near East could be a chaotic place. His ancestors had established Assyria as the most extensive empire in the world, yet the civilisations they had subjugated never stayed silent for long. Ashurbanipal began his reign by completing the invasion of Egypt his father had begun, and in subsequent decades he was forced to extinguish numerous rebellions, including a terrible civil war begun by his own brother.

The record of these conquests is inscribed in the stone relief panels that once adorned his palace. In terms of technical skill, these exquisitely detailed carvings represent the high-water mark of Assyrian art. But the cruelty they depict is shocking. In one scene, prisoners facing execution are forced to crush the bones of their fathers with a mace. There is no pathos for the victims here – the panels serve to glorify the king, by showing the ruthless lengths he could go to in order to impose his will. One leaves this brilliant, at times compellingly gory, exhibition with the impression that for this powerful ancient ruler, civility and brutality went hand in hand.

“The royal lion hunt”, 645-640 BC , North Palace, Nineveh, Iraq

These panels, which depict Ashurbanipal hunting lions, are among the most famous works of Assyrian art. Since their rediscovery at Nineveh, they have astounded viewers with the intricate iconographical detail of the king’s clothing and headwear, while the realism of the lions’ taut musculature lends great dynamism to the scene.

Lion hunts like these were public ceremonies. They enabled the king to cast himself before his subjects in the role of royal hero, taming the wild forces of nature. The roots of this symbolic act extend deep into the past; when, in one scene in the upper register, Ashurbanipal raises a lion to its hind legs by its throat, he strikes a pose that had adorned the imperial Assyrian seal for more than two centuries. Yet the artist of these panels also reveals how Ashurbanipal had modernised the image of king. There is a small reed pen protruding from his belt: the proud emblem of his learning.

Stone stele depicting Ashurbanipal (right), shown with a ritual basket on his head with cuneiform inscription (668–65 BC ), South Iraq, Marduk temple (Babylon). His brother Shamash-shumu-ukin (left) carved with cuneiform inscription (668–55 BC ), South Iraq, Temple of Nabu (Borsippa)

Together, these sculptures offer a remarkable insight into how Ashurbanipal sought to present himself as a dynamic, constructive ruler – and how he would silence conflicting interpretations. In the stele to the right, Ashurbanipal is depicted, with all the customary finesse of detail in his beard, clothing, and conical ruler’s headdress, restoring a temple in Babylon, a territory in Assyria. Cuneiform text lists his achievements.

Babylon, however, was ruled by Ashurbanipal’s older brother, Shamash-shumu-ukin. Their father, king Esarhaddon, had left the throne of Assyria to Ashurbanipal, his favourite son, and had sought to placate Shamash-shumu-ukin by installing him as king of Babylon. Steles like this show how Ashurbanipal undermined his brother’s rule by undertaking building projects in regions under his jurisdiction.

Shamash-shumu-ukin revolted against his younger brother in late 652 BC , supported by a coalition of Assyria’s enemies; less than four years later, after a long and brutal siege at the gates of Babylon, he was dead. Tellingly, the image of Shamash-shumu-ukin carved in the stele on the left – engaged in the restoration of the Temple of Nabu, alongside his brother – was defaced in the years following his failed rebellion.

Fragment of a wall panel showing the head of a eunuch, 710-705 BC , Khorsabad, Iraq

The breadth and diversity of Ashurbanipal’s empire demanded extensive infrastructure and efficient bureaucracy. The king created an innovative “Royal Mail” service, by which information could be dispatched quickly and effectively between the officials in command of the empire’s various states. These officials, known as “magnates”, were often eunuchs who had submitted to castration to prove that they prized loyalty to the king over continuing their bloodline. The beardless features of this official indicate that he belonged to this elite group.

A significant proportion of the clay tablets found in Ashurbanipal’s library are letters, documents and other ephemera, detailing the minutiae of his rule. They give evidence of the extensive organisational structure that enabled him to extend the boundaries of his empire further than any of his predecessors.

“The Banquet Scene of Ashurbanipal”, 645-640 BC , North Palace, Nineveh, Iraq

Most surviving Assyrian art depicts battles and animal hunts, so this bucolic panel is unusual. It shows Ashurbanipal, relaxing at a banquet in the palace gardens with his queen, Libbali-sharrat, surrounded by date palms and vines burdened with ripe grapes. His bow rests on the table at his side, and behind him, slaves stand fanning his back. At the left of the panel, however, there is a grisly reminder of the expense at which this peaceful moment has been bought. From a tree – directly in the king’s eyeline – hangs the severed head of Teumman, the defeated king of Elam.

Cuneiform clay tablet vitrified in the intense heat of the burning of the South-west Palace in Nineveh”, 700-600 BC , Nineveh, Iraq

Less than two decades after Ashurbanipal died, his kingdom lay in tatters. In around 609 BC , the Babylonians invaded and sacked the palace at Nineveh, setting fire to the great library. However, although the Babylonian’s act of arson destroyed many of the clay texts Ashurbanipal had so meticulously compiled, many more were hardened in the flames, preserving them for posterity. You can’t help but reflect on the vicissitudes of destruction and preservation over the course of history – the remarkable tales of how knowledge has been transmitted across millennia, or else lost irrevocably.

This process, of course, continues to the present. When Islamic State established their caliphate in Mosul, between 2014 and 2017, they took to the “heathen” effigies of Ashurbanipal’s palace with pickaxes and bulldozers. Aptly, the exhibition concludes with a look at the work of the Iraq Emergency Heritage Management Training Scheme, established by the British Museum in order to develop the skills of archaeologists in the region, such that Iraqi heritage might be preserved in the event of future conflicts.

I am Ashurbanipal, king of the world, king of Assyria British Museum until February 24th 2019