YOU don’t notice it at first. But all over the archaeological site at Palmyra you see the same symbol—on architraves and lintels, and especially on the magnificent Bel temple. The line of carved stone eggs, each one separated by a dart or arrow pointing downwards, was first used by the Greeks on the Erechtheum behind the Acropolis. It was brought to Syria by the Romans, who built Palmyra and decorated its monuments with the egg, meaning life or rebirth, and the arrow, war or death. For centuries the two were carved together, signifying the duality of human existence.

The jihadists of Islamic State (IS) understand the meaning of symbols better than most. Over the past year they have projected fear across Iraq and Syria, posting footage of people they have beheaded. In February they released videos of ancient statues being smashed in the museum at Mosul in northern Iraq and, later, the bulldozing of the ancient Assyrian capital, Nimrud, 20 miles (32km) away. IS wants to do away with “false idols”, promising instead an Islamic caliphate that threatens to be as extreme as it is thuggish.

So when IS overran Palmyra on May 20th, many expected the worst. Within days social media were flooded with pictures, endlessly repeated, of young men who had been decapitated in Tadmur, the name Syrians use for the ruins and the tiny town nearby. Their hands had been tied behind their backs, blood pooling in the street. A single black IS flag was raised on the citadel that overlooks the Roman ruins, one of the site’s few medieval Islamic buildings. The jihadists were reported to have entered the local museum, smashed two statues, both plastercasts as the originals had been removed, and posted their own guards outside. Western archaeologists were afraid to call their Syrian colleagues for fear of putting their lives at risk.

Palmyra’s symbolism is powerful, and not lost on IS. At its height the city was the centre of an empire that covered, among other territories, all of modern Syria and Israel and parts of Iraq and Saudi Arabia. It is still one of the most impressive archaeological sites in the Middle East, with a small theatre, temples, monumental gateways, a long colonnaded street, a crossroads monument known as a tetrapylon, and, at the city limits, extensive necropolises with Roman-era tombs. Approaching visitors see a mirage in the distance, the salt pans of the oasis with its feathery palms, and then the luminous ruins slowly taking physical shape out of the plain. They are, an early traveller wrote: “The most glorious structures in the world.”

An oasis on the route between the Mediterranean and the Euphrates, Palmyra was always important. Having been allowed by Hadrian, the Roman emperor, to take charge of its own finances in 129AD, the city made its money from taxes levied on goods from the western Roman empire that were traded for imports from the Arabian peninsula, India and China. Third-century Syria was also a maelstrom of religions, as pagan cults thrived alongside monotheistic religions, some worshipping the sun. Jews and Christians had settled there, too, and Christian doctrine was the subject of much debate. In 269 Palmyra’s Queen Zenobia, taking advantage of a moment of Roman weakness, invaded Egypt to the south-west and then occupied Anatolia to the north, cleaving the Roman empire in two. But within a short time a new, tougher emperor, Aurelian, retaliated. In 272 Palmyra was forced to surrender. Years of tumult were interspersed with periods in which Palmyra was largely ignored. When the Muslim Umayyad empire reached the city in the mid-seventh century, the main trade routes had shifted north and Palmyra had become a backwater. The Umayyads adopted and absorbed the city’s Roman and Byzantine infrastructure and made contributions of their own. A mihrab, showing the direction of Mecca, was built in the Bel temple, indicating that for a time it was a mosque. But carved reliefs of veiled women suggest that many images now regarded as Islamic in fact have roots that are far older.

INTERACTIVE: Fragile treasures - UNESCO World Heritage sights in danger Zenobia features in the writings of medieval Arab chroniclers, such as Muhammad ibn Jarir al-Tabari. But the earliest surviving picture of the ruins was painted only in 1691, and nearly another century would pass before two British architects, James Dawkins and Robert Wood, published a magnificent folio volume of drawings, “The Ruins of Palmyra”, that would revolutionise architectural taste in England. The egg-and-dart motif became a stalwart of late-Georgian decoration, and the famous Palmyrene rose began to appear on the ceilings of many a grand English country house. Over the next century, Queen Zenobia’s story was repeated and embellished as she slowly morphed into the Braveheart of the Arab world.

Queen of the desert

Edward Gibbon wrote that she had large black eyes that “sparkled with uncommon fire, tempered by the most attractive sweetness”. Giovanni Battista Tiepolo painted her, and so, later, did Herbert Gustave Schmalz, who, despite his name, was an Englishman. When Lady Hester Stanhope, the niece of William Pitt, became the first European woman to visit Palmyra in 1813, she rode in on horseback, dressed in Arab robes, which made her forever known in Britain as “the Queen of the Desert”, thus explicitly cementing the link to Zenobia. The story of Palmyra’s sovereign spoke to a society that would soon be ruled by a queen of its own.

Although the uprising that Zenobia led lasted no more than three years, her symbolism lived on, growing ever more exaggerated. Some saw her as a proto-Christian or even a proto-Jewish legend. In recent times she has personified Arab insurrection against the West. As IS entered Palmyra, among the many losses reported was the disappearance of the last surviving northern bald ibis in the Middle East (pictured). The bird had been named Zenobia.

If Palmyra inspired European fantasies about the “romance” of Arabia, 20th- and 21st-century Syrian mythology about the city has been of a much darker hue. After taking power in 1970 the Assads, first Hafez then after 2000 his son Bashar, carefully constructed the identity of Syria around their family rather than national treasures such as Palmyra. Their faces were plastered on billboards and car-stickers with slogans such as al-Assad ila al-abad (Assad for eternity). On sale in the souks of Damascus there are more fridge magnets featuring the Assads than Palmyra or Krak des Chevaliers, the Crusader fortress that T.E. Lawrence once described as the “most wholly admirable” castle in the world.