In the summer of 1348 a ship put in at the little Dorset port of Melcombe, near modern Weymouth, and something stepped ashore with the sailors that would kill perhaps half the people in England within two years. There were no sirens, no warnings, no understanding of what was happening. People simply began to die — in the towns, in the villages, in the great houses and the meanest hovels alike — faster than the living could bury them. We call it the Black Death, and nothing in English history before or since has matched the sheer scale of its destruction.

The disease had been travelling for years before it reached England, creeping along the trade routes out of central Asia, through the Black Sea ports and across the Mediterranean. It rode in the holds of merchant ships, in the fleas that lived on the black rats that lived among the cargo. Medieval people had no idea about any of this. They blamed bad air, the alignment of the planets, the sins of mankind, and — horrifyingly — their neighbours. What they could not do was stop it.

The symptoms were as terrifying as the death rate. It usually began with the swellings the disease is named for — buboes, hard and agonising lumps in the groin, the armpit and the neck, sometimes growing as large as an apple. Fever and delirium followed. Black blotches spread under the skin from internal bleeding, which is very likely where the later name “Black Death” comes from. Most of those who showed the swellings were dead within a week. A second, even deadlier form attacked the lungs and could kill in a day or two, passing straight from person to person on the breath.

Contemporary writers struggled to convey the horror without sounding like they were exaggerating, and yet the surviving accounts are remarkably consistent. They describe whole households dying together, fields of livestock wandering untended because there was no one left to herd them, and great pits dug outside the towns into which the dead were tipped in layers. One chronicler wrote that the living were scarcely able to bury the dead. Priests, who had to attend the dying, perished in enormous numbers, which only deepened the sense that even the Church could offer no shield.

Estimating the toll is difficult, but historians generally reckon that somewhere between a third and a half of England’s population died in that first wave between 1348 and 1350. Think about what a number like that actually means. It means that almost everyone alive lost members of their own family. It means villages that had stood for centuries were simply abandoned, their houses left to rot back into the earth — and you can still trace the bumps of some of these “lost villages” in English fields today.

And here is where the story takes a strange and important turn. The Black Death was a catastrophe, but catastrophes reshape the world that survives them. Before the plague, England was crowded with people and short of land; labour was cheap and the peasant who worked the soil had very little bargaining power. After the plague, that arithmetic was turned completely upside down. Suddenly there were far too few workers for the land that needed working, and a surviving labourer could, for the first time in living memory, demand higher wages — and get them, because the alternative was for the crops to rot in the fields.

The landowners were appalled. Parliament rushed through laws trying to freeze wages at their old levels and to force people to work for whoever demanded it, but you cannot legislate away supply and demand for long. Resentment built on both sides through the second half of the century, the lords furious at having to pay more and the labourers furious at being told they could not. That pressure would eventually explode, but that is a story for the next instalment.

The plague did not vanish after 1350, either. It came back in waves for the next three centuries, never quite as devastating as the first onslaught but always present, always feared, lurking in the background of English life. Each return reminded people how fragile everything was.

It is tempting, looking back, to flatten the Black Death into a single grim statistic. But what makes it matter is the way it cracked open a rigid society and let something new grow in the gaps. Wages rose, old certainties wobbled, and ordinary people began — slowly, painfully — to glimpse the idea that the world they were born into was not fixed forever. In the next part of this series we’ll see where that new boldness led, when in 1381 the common people of England marched on London itself.