Did the Trojan War really take place? The Foreign Secretary certainly thinks so. ‘The Iliad must have happened,’ Boris Johnson once told me. ‘That description of the Trojans attacking like birds is so chilling, it must be true.’

Boris was referring to the beginning of Book 3 of the Iliad, where the Trojans ‘advanced with cries and clamour, a clamour like birds, cranes in the sky, flying from the winter’s storm and unending rain, flowing towards the streams of the ocean, bringing the clamour of death and destruction to Pygmy tribes, bringing evil and strife at the break of day’.

You only have to stand on top of the ruined towers of ancient Troy, on the western shores of Turkey, to agree with Boris.

There, below your feet, stand the city’s mighty cyclopean walls, around which Achilles chased poor Hector three times. Those walls slope, just as Homer said. And, on their western side, the walls fall away — at the same weak spot where Athena told the Greeks to attack. Archaeologists have even found a thrilling subterranean layer of scorched objects, arrowheads, skulls and butchered skeletons, suggesting the city was sacked in around 1200 BC. And, beyond the walls, the River Scamander meanders down to the wine-dark sea, as it does in the Iliad.

Whether the Trojan War happened or not, it richly deserves its lavish, new, eight-part BBC/Netflix adaptation, Troy: Fall of a City (which starts on BBC One on Saturday). Created and co-written by David Farr, scriptwriter for John le Carré’s The Night Manager, it’s the most expensive drama in BBC history, costing £16 million.

Farr has played fast and loose with Homer’s text, injecting anachronistic echoes of Shakespeare and Chaucer. The dialogue is faux-historical clunky, in true sword-and-sandal fashion: ‘Your quarters are in the south of the palace and afford the finest views of the region.’ The Trojan War without Homer’s verse is Hamlet without the prince.

David Farr has also recreated Troy, not by the Aegean, but in Cape Town. And he concentrates on the story of Helen of Troy and Paris, the spoilt son of Priam, King of Troy. Helen’s elopement with Paris may have sparked the Trojan War; but the lovers often take a back seat in the Iliad. Surprise, surprise, the most beautiful woman in the world, dressed in a flimsy, low-cut peplos, takes centre stage on telly.

The drama concentrates on the Trojan side of the story because, Farr says, we know the Greek story so well. Not that he’s the first to tell the story from the Trojan point of view. That’s exactly what the Trojan hero Aeneas does in the Aeneid, the greatest Roman epic, when he recalls fleeing Troy to found Rome. In fact, there’s an awful lot about the Trojan side in the Iliad, too. There’s the heart-breaking scene where Hector says a tender goodbye to his wife, Andromache, ‘laughing through her tears’, as his baby son Astyanax cries at the sight of his father’s armour and the nodding horsehair plume on his helmet. Then there’s the Iliad’s agonising conclusion, where Priam clutches Achilles by the knees and begs for his son Hector’s body.

Still, Farr’s playing around with the greatest of all epics doesn’t matter much. Like Shakespeare’s works, Homeric epic is so protean and robust that it can bear any number of interpretations. The Iliad’s characters and stories have become so elemental that they assume a life of their own. They can be pillaged and cannibalised at will for their individual symbolic value. You can pick and choose iconic elements — Achilles’s strength, Helen’s beauty — and do what you want with them, without having to import the complete, authentic story.

The Trojan War is crammed with firsts. It’s the first great war story. As Thucydides said, it’s also the first recorded time the Greek tribes fought together as a single confederation. The war contains the first, greatest piece of military espionage, in the Trojan Horse (which appears in the Odyssey, not the Iliad). The Odyssey has the first flashback in literature, too, when Odysseus recounts his adventures at sea.

It is a miracle. Two fully formed, unprimitive epics jumped out of nowhere, with nothing to match them in previous, surviving literature. The Iliad and the Odyssey mark the beginning of Western European literature, and the Western European mind has been haunted by the Trojan War ever since.

The two epics were peerlessly influential in the classical, renaissance and modern worlds — in art, literature and thought. It’s only logical that television has now been bewitched by the greatest story ever told.