A civilisation that lasted three thousand years should not exist. Empires collapse, languages die, religions are forgotten. Yet Ancient Egypt endured — pharaoh after pharaoh, flood after flood — longer than the gap between Julius Caesar and the present day. The question worth asking is not how it rose, but how anything that durable finally fell.

It began around 3150 BC, when a king named Narmer united the two kingdoms of Upper and Lower Egypt into a single state. His successors planted a capital at Memphis, commanded the Nile delta's labour, and built elaborate tombs to declare their divinity. The institution of kingship became the engine that held everything together.

The Nile was the machine beneath the engine. Every year it flooded, retreated, and left behind a strip of black silt so fertile that Egypt could feed far more people than its desert surroundings should have allowed. That surplus funded scribes, priests, armies, and monuments on a scale the ancient world had never seen.

The Old Kingdom, between roughly 2686 and 2181 BC, produced the Giza pyramids and the Great Sphinx — feats of quarrying and engineering that remain astonishing. But the same land-grant system that rewarded the builders slowly bled the treasury dry. Severe droughts finished the work, and the central government collapsed into a century of famine and civil war.

Egypt reunited, fractured again, and reunited once more. The New Kingdom, from around 1549 BC onward, was its peak: pharaohs pushed the empire from Nubia to Syria, and Ramesses the Second fought the Hittites to a standstill at Kadesh before signing what is recorded as history's first peace treaty, around 1258 BC. His name is carved on more monuments than any other ruler in Egyptian history.

Then the long decline. Sea Peoples raided the coasts. Libyan chieftains seized the delta. Kushite kings swept in from the south and briefly rebuilt an empire nearly as large as the New Kingdom's — before Assyrian armies sacked Thebes and pushed them back. Each conqueror came, ruled, and was eventually absorbed or replaced.

Persia took Egypt in 525 BC. Alexander the Great walked in without a battle in 332 BC, welcomed as a deliverer. His successors, the Ptolemies, ruled from Alexandria, built the famous Library there, and dressed as pharaohs — but the real power was drifting steadily toward Rome. In 30 BC, after Cleopatra the Seventh and Mark Antony were defeated at the Battle of Actium, Egypt became a Roman province. The age of the pharaohs was over.

Rome taxed Egypt hard and shipped its grain across the Mediterranean. Christianity spread through the country from the first century AD onward, and by 391 the emperor Theodosius the First had banned pagan worship outright. Temples were closed or converted to churches. The priests who could still read hieroglyphs grew fewer each generation, until the knowledge was simply gone.

In 642, Arab forces completed their conquest of Egypt, ending a millennium of Greco-Roman rule. The language of the Nile valley shifted to Arabic. The old gods were forgotten. What remained were the stones: pyramids that had already stood for two thousand years before Rome existed, a writing system that had recorded everything from love poetry to surgical instructions, and the idea that a river's annual gift could sustain a civilisation across thirty centuries. That idea proved harder to bury than any pharaoh.