Anyone who has visited Trafalgar Square in London will know that tourists tend to gravitate to one feature above all others: the set of four enormous bronze lions, each weighing seven tonnes, at the foot of Nelson’s Column. They were designed by the British painter and sculptor Edwin Landseer – who used the body of a dead lion from London Zoo as a model – and installed in 1867. 

Landseer’s big cats are among the most famous lions in Western art. There are, of course, many others. Indeed, artists have been depicting lions for millennia, to the point that, as a motif, they are so commonplace they are often overlooked.

For instance, lions often appear as faithful companions in paintings of Saint Jerome. Rubens painted dramatic lion hunts. So did Delacroix. In Henri Rousseau’s The Sleeping Gypsy (1897), a moonlit lion sniffs a figure sleeping beside a mandolin. Meanwhile, a spectacular orange lion prowls the streets outside a jailhouse in Port of Spain, in a hallucinatory painting from 2015 by the Scottish artist Peter Doig. 

An exhibition in Tehran featured hundreds of lions of Iranian art – some were created thousands of years ago

Lions are a staple element in heraldry. An ancient bronze statue of a winged lion is the symbol of Venice. In the same city, a splendidly slumberous lion guards the monument to the sculptor Canova in the church of Santa Maria Gloriosa dei Frari.

In short, the list of lions in art is endless. Earlier this year, the Iranian sculptor Parviz Tanavoli curated an exhibition in Tehran featuring hundreds of lions in the art of his own country. Some of the artefacts on display were created thousands of years ago.

The Lion Man

What do all these representations of lions signify? And when did they become so popular? Living with Gods, a new exhibition exploring religious belief at the British Museum, answers the latter question, if not the former, because it reveals that lions have been an essential component in the matrix of visual representation since the dawn of artistic expression.

The evidence for this is an ivory sculpture, 31cm (12.2in) tall, depicting a hybrid creature, with a human body and a lion’s head, carved from the tusk of a mammoth 40,000 years ago. Its fragments were discovered in a cave in south-west Germany during the 20th Century. Painstakingly reconstructed, it is known today simply as ‘The Lion Man’. “It is a masterpiece,” says Jill Cook, the exhibition’s curator, and an expert on Ice Age art. “Incredibly original, technically brilliant, and with this extraordinary spiritual power.”

As Cook explains, the artistry of the sculpture is special: the calves of the figure, which appears to be standing on tiptoes, are, she says, “beautifully turned”, while behind one ear, we can see a “little furrow”. “That furrow is formed by the muscles contracting when a lion pricks its ears to listen,” Cook continues. “So, this creature is alert, and in front of the ear, you can see the auditory canal. In other words, this isn’t a man wearing a mask. It is a very detailed lion’s head.”

This powerful image shows the human mind working as ours does: storytelling, thinking, trying to give meaning to life – Jill Cook

The Lion Man was probably based on observation of European cave lions, which, although now extinct, were plentiful during the Ice Age, when they were, says Cook, “the top predator”. While we can identify the subspecies of the Lion Man, though, its meaning remains elusive. “We know that it depicts the fiercest creature in the environment, and is made of material from the largest mammal,” says Cook. “So, it is about humans trying to find their place in nature, to transcend or perhaps even reshape nature, or to reach out through the cosmos. Perhaps this is an avatar, part of a creation story, we know not what.”

She continues: “But, in a way, I don’t care what its meaning was. All art communicates – and this is a very powerful image, which shows the human mind working as ours does: storytelling, thinking, trying to give meaning to life.”

Poised or ferocious?

The Lion Man dates from a very long time ago – an obscure period of ‘deep history’, tens of thousands of years before the invention of the written word. A quick stroll through the British Museum, though, reveals that, from the advent of recorded history, lions once again played a major role in ancient art.

Recently, one of Cook’s colleagues, St John Simpson, an archaeologist and Near East specialist, took me on a whistle-stop tour of the museum’s most celebrated ancient lions. We met in the Great Court, beside the so-called Lion of Knidos, a colossal marble beast from the Hellenistic era. Carved at some point (opinions differ) between the 4th and 2nd Centuries BC, it once topped a tomb in the coastal city of Knidos in south-west Turkey. “For me, the great thing about this lion,” says Simpson, “is that it’s the biggest example we’ve got of the phenomenon of the cat’s eye – because his eyes were originally inlaid with glass.”

For Simpson, the lion is one of the most important motifs of ancient art. “The lion dominates the megafauna of the ancient Near East in art as well as in reality from the late fourth millennium BC onwards,” he says. “And in art, there are two versions of leonine might.”

The first, he explains, was prevalent in ancient Egypt and again during the Hellenistic age, as exemplified by the dignified Lion of Knidos: “In these periods, carvers represent the majesty and solemnity of the lion,” Simpson says. “They appear poised, like scaled-up cats.” In an adjoining gallery, he shows me a sleek granite lion, which also had inlaid eyes, commissioned by the 18th Dynasty pharaoh Amenhotep III, who ruled Egypt during the 14th Century BC. It is surprisingly placid and graceful.

Yet, according to Simpson, in between Egypt’s New Kingdom and the time of the Hellenistic world, lions appear in ancient art in a very different guise. “Particularly during the Assyrian period and the Achaemenid [ie Persian] Empire, the iconography of the lion changes radically, and artists capture the fierceness and ferocity of the beast,” he says. “So, lions are shown roaring, snarling, open-mouthed.” 

He leads me to a colossal guardian lion, weighing 15 tonnes, one of a pair that symbolised Ishtar, the Assyrian goddess of war, which once flanked the entrance to her temple built by Ashurnasirpal II (r 883-859 BC) at Nimrud. It is a terrifying vision, with a thick mane and pelt, powerful legs and forepaws, and an angry expression, captured mid-roar. “Here we have the ‘fierce’ lion – it’s a completely different version of leonine might,” Simpson says. “Sadly, its brother was destroyed by Daesh,” he says, referring to the so-called Islamic State.

Simpson says that this “fierce” model of “leonine might” proved popular: elsewhere, he shows me a panel of glazed bricks depicting another snarling lion, this time Babylonian. Pacing and proud, he once decorated the throne room of Nebuchadnezzar II, who ruled from 605-562 BC, in the ancient city of Babylon in modern-day Iraq.

For Simpson, though, the golden age of lion imagery in the ancient world coincided with the Neo-Assyrian Dynasty, which dominated the Near East from the 9th to 7th Centuries BC. 

A short walk brings us to one of the treasures of the British Museum: a group of gypsum wall-panel reliefs from an Assyrian palace at Nineveh, depicting the royal lion hunt of Ashurbanipal (r 668-627 BC), the last great Assyrian king. Simpson describes the complex series of related scenes as “a whole landscape of lion hunting”, as the king and his courtiers, aided by soldiers and keepers restraining fierce mastiffs, set about slaughtering lions. “Clearly, this was a real place where they killed lions – an artificially enclosed part of a natural landscape,” Simpson says. “The dynamism is extraordinary.”

Arguably, the most memorable and affecting elements are the many different lions, both male and female, skewered by arrows, who twist and turn in paroxysms of agony. Their death throes are captured in a stunningly inventive range of ways: some hurtle through mid-air, stricken by the initial shock of fatal pain, while others lie prone, giving up the ghost. One slumps on its haunches and spews out gore into the dirt. 

For a modern audience, these poor and surprisingly naturalistic creatures elicit sympathy. But Simpson cautions against assuming ancient viewers felt the same way. “I’m not sure an ancient Assyrian would have viewed them like that,” Simpson says. “That would undermine the power of the art. Ultimately, showing multiple scenes of death underlined the power of the king.”

Alastair Sooke is Art Critic and Columnist of The Daily Telegraph

If you would like to comment on this story or anything else you have seen on BBC Culture, head over to our Facebook page or message us on Twitter.

And if you liked this story, sign up for the weekly features newsletter, called “If You Only Read 6 Things This Week”. A handpicked selection of stories from BBC Future, Culture, Capital and Travel, delivered to your inbox every Friday.