In some parts of England, people with communicable diseases such as smallpox were isolated in so called Pest Houses like this one in Findon.

“The smallpox was always present, filling the churchyards with corpses, tormenting with constant fears all whom it had stricken, leaving on those whose lives it spared the hideous traces of its power, turning the babe into a changeling at which the mother shuddered, and making the eyes and cheeks of the bighearted maiden objects of horror to the lover.”
T.B. Macaulay

For at least 3,000 and perhaps as much as 6,000 years, smallpox was one of the world’s deadliest diseases. In countries where it was endemic, it was a disease of childhood, killing up to 80% of children infected. A person fortunate to escape infection in childhood who then caught the virus as an adult, had a 30% chance of dying. Either way, those who survived the disease were left with lifelong scars but also with lifelong immunity, so they could neither catch the disease nor transmit it to others.

Transmission was from person to person, including from droplets in the air from sneezing, coughing, or even breathing. Worse, body fluids on things like clothing or bedding could carry live viruses.

In countries where the disease was new, with no such protective pool of survivors, the infection rate was horrific and the death rate catastrophic. For example, in the Americas, it’s estimated that smallpox, measles and influenza killed 90% of the native population. Children and adults were affected alike.

Even in Europe, though, smallpox changed the fate of nations. In Britain, it played a part in the downfall of the royal house of the Stuarts. Smallpox put Charles II out of action for several weeks during a crucial time in the Civil War, and killed his brother Henry. Had this Protestant prince been alive when James II’s Catholicism caused the rift with the people, history might have been quite different. All of the new king’s sons died young, one of smallpox. He was succeeded by his daughter Mary and his son-in-law and nephew William of Orange.

Mary died of smallpox towards the end of 1694. Thomas Macaulay described her death as follows:

That disease, over which science has since achieved a succession of glorious and beneficient victories, was then the most terrible of all the ministers of death. The havoc of the plague had been far more rapid; but the plague had visited our shores only once or twice within living memory; and the small pox was always present, filling the churchyards with corpses, tormenting with constant fears all whom it had not yet stricken, leaving on those whose lives it spared the hideous traces of its power, turning the babe into a changeling at which the mother shuddered, and making the eyes and cheeks of the betrothed maiden objects of horror to the lover. Towards the end of the year 1694, this pestilence was more than usually severe. At length the infection spread to the palace, and reached the young and blooming Queen. She received the intimation of her danger with true greatness of soul. She gave orders that every lady of her bedchamber, every maid of honour, nay, every menial servant, who had not had the small pox, should instantly leave Kensington House. She locked herself up during a short time in her closet, burned some papers, arranged others, and then calmly awaited her fate.

During two or three days there were many alternations of hope and fear. The physicians contradicted each other and themselves in a way which sufficiently indicates the state of medical science in that age. The disease was measles; it was scarlet fever; it was spotted fever; it was erysipelas. At one moment some symptoms, which in truth showed that the case was almost hopeless, were hailed as indications of returning health. At length all doubt was over. Radcliffe’s opinion proved to be right. It was plain that the Queen was sinking under small pox of the most malignant type.

All this time William remained night and day near her bedside. The little couch on which he slept when he was in camp was spread for him in the antechamber; but he scarcely lay down on it. The sight of his misery, the Dutch Envoy wrote, was enough to melt the hardest heart. Nothing seemed to be left of the man whose serene fortitude had been the wonder of old soldiers on the disastrous day of Landen, and of old sailors on that fearful night among the sheets of ice and banks of sand on the coast of Goree. The very domestics saw the tears running unchecked down that face, of which the stern composure had seldom been disturbed by any triumph or by any defeat. Several of the prelates were in attendance. The King drew Burnet aside, and gave way to an agony of grief. “There is no hope,” he cried. “I was the happiest man on earth; and I am the most miserable. She had no fault; none; you knew her well; but you could not know, nobody but myself could know, her goodness.” Tenison undertook to tell her that she was dying. He was afraid that such a communication, abruptly made, might agitate her violently, and began with much management. But she soon caught his meaning, and, with that gentle womanly courage which so often puts our bravery to shame, submitted herself to the will of God. She called for a small cabinet in which her most important papers were locked up, gave orders that, as soon as she was no more, it should be delivered to the King, and then dismissed worldly cares from her mind. She received the Eucharist, and repeated her part of the office with unimpaired memory and intelligence, though in a feeble voice. She observed that Tenison had been long standing at her bedside, and, with that sweet courtesy which was habitual to her, faltered out her commands that he would sit down, and repeated them till he obeyed. After she had received the sacrament she sank rapidly, and uttered only a few broken words. Twice she tried to take a last farewell of him whom she had loved so truly and entirely; but she was unable to speak. He had a succession of fits so alarming that his Privy Councillors, who were assembled in a neighbouring room, were apprehensive for his reason and his life. The Duke of Leeds, at the request of his colleagues, ventured to assume the friendly guardianship of which minds deranged by sorrow stand in need. A few minutes before the Queen expired, William was removed, almost insensible, from the sick room.

(In my book To Mend a Proper Lady, a girls school is caught up in a smallpox epidemic, causing my heroine Ruth Winderfield to flee with three girls for whom she is responsible plus two more she promises to deliver home on her way back to London. Of course, she becomes trapped at the home of the girls’ guardian, nursing them and others who fall ill.)