On March 11, amid the cacophony of digital noise about Kate Middleton’s health, one joking tweet went viral for its partial truth. “The Princess of Wales is missing and the spare Prince is in exile and the King is treating his cancer with herbs. If this were the 1300s France would be looking to invade,” the ACLU’s head of digital engagement wrote in a tweet liked by some 282,000 people.

For millennia, royals suffering from chronic illnesses have found themselves in a complicated position: show weakness, and the privileged mystique may be lost. “Above all things our royalty is to be reverenced, and if you begin to poke about it you cannot reverence it,” 19th-century journalist Walter Bagehot noted. “Its mystery is its life. We must not let in daylight upon magic.” 

The bravery of King Charles III and Catherine, Princess of Wales, in sharing their cancer diagnoses, may signal a new era of medical transparency from the British royal family. But for many centuries, royals simply could not be honest about the fact that they were mere mortals, as their countries’ survival could depend on their own.

A ruler’s death could be so perilous that in some cultures it was not even acknowledged. According to the journal African Affairs, “The king never dies” was the motto of the Temne people of northern Sierra Leone. When a king was ill, a bulletin went out that said, “The king is sick.” When he died, he was simply reported to be “very sick.” The body was hidden, a new king was elected, and the death of the previous ruler was not acknowledged until after the new monarch’s coronation.

“The death of a king could spell catastrophe for some or salvation for others, depending on who they had supported and who was to succeed,” historian Suzie Edge writes in Mortal Monarchs: 1000 Years of Royal Deaths. “The new monarch could bring with them wars and bankruptcy, or they could bring peace and wealth. Whenever a monarch died there followed a time of uncertainty and concern.”

This meant that the lengthy illness of a royal ruler caused great unease in a kingdom. A covetous courtier, sibling, or even a monarch’s own child could strike out and take power. As historian and author Julia Fox notes in Sister Queens, during the 16th century, Queen Juana I of Castile’s reported mental illness was seized upon (and probably exaggerated) by her father, husband, and son—the Emperor Charles V—in order to strip her of her power and rule in her name.

To avert such disasters, monarchs were often forced to pretend they were well when they were anything but. In 1553, 15-year-old King Edward VI of England and Ireland was slowly dying of tuberculosis. His dogmatic Protestant handlers were terrified that the rampant rumors of the young king’s infirmity would encourage his Catholic sister Mary or his more liberal sister Elizabeth to seize the throne before his death. But according to biographer Chris Skidmore, their attempts to prove that all was well backfired spectacularly:

“To reassure the crowds assembling nervously at Greenwich, Edward made his final appearance, peering out from his window on Saturday 1 July. The sight of his thin and wasted body only confirmed the worst, for those watching from below looked on horrified, saying he was doomed, and that he was only shown because the people were murmuring and saying he was already dead, and in order that his death, when it should occur, might the more easily be concealed.”

Louis XIV, the Sun King, blazed as the divinely ordained absolute autocrat of France, but in 1686 the aging king, already suffering from chronic gout and other illnesses, developed a painful anal fistula. He underwent an excruciating surgery to remove the fistula but continued his act as superman, only crying, “My God” once during the agonizing ordeal.

“Almost as extraordinary as Louis’s fortitude under the knife was the fact that he actually held a council meeting that night,” Antonia Fraser writes in Love and Louis XIV. “The next morning he also held his normal lever for the court, although the sheen of perspiration could be seen on his dead-white face.”

When he mentioned the affair, it was simply to downplay its severity and effects. “People who weren’t here believe my illness to have been great,” he claimed. “But the moment they see me, they realize that I have scarcely suffered.”

It was not just monarchs whose health was a national concern. Until the 20th century, marriages between royal households were powerful tools of dynastic diplomacy, and having a stable of healthy and fertile young princesses and princes to marry off could make or break a country’s fortune. Royal portraitists attempted to hide infirmities or sickliness in their subjects, often forcing royals to send their own envoys to confirm a potential prospect’s health themselves.

After smallpox struck, killing one of her daughters and rendering her most beautiful daughter disfigured, Empress Maria Theresa of Austria (Marie Antoinette’s mother) offered up her other daughters to Charles III of Spain, writing:

“I grant you with real pleasure one of my remaining daughters to make good the loss…. I do currently have two who could fit, one is the Archduchess Amalia, who is said to have a pretty face and whose health should promise a numerous progeny, and the other is the Archduchess Charlotte, who is also very healthy and a year and seven months younger than the King of Naples.”

The irony, of course, is that until the modern medical age, almost everyone was chronically ill with something—be it dysentery, dropsy, tuberculosis, syphilis, consumption, asthma, or a host of other lesser conditions that would now be manageable. King Henry VIII—with a chronic oozing sore on his leg that left him consistently irritable—probably had type two diabetes. Queen Anne of Great Britain most likely had lupus, as well as chronic “sore eyes” that gossip mongers claimed were the result of her father, King James II, giving her mother an STD that affected the birth canal.

As the Industrial Revolution brought royal gossip to the masses, the public became obsessed with everything about royals, including their health. In Britain, daily Court Circulars reported on the most mundane of royal ailments. “We regret to state that his Majesty has experienced another attack of the gout,” a British periodical reported in 1837. “And that the Queen is suffering from a cold.”

But in terms of major, chronic illnesses, there was still subterfuge and understandable secrecy. King George III of Britain, the 18th century’s famed “mad monarch,” suffered greatly with what was probably the genetic disorder porphyria, which caused episodes of excruciating pain, hallucinations, and delusions (some think his ancestor Mary, Queen of Scots, may have suffered with this as well).

Daily bulletins issued by doctors concerning the king’s health became a political minefield, with George, Prince of Wales, fighting to expose his father’s true condition (and thus obtain a regency); the king’s protective wife, Queen Charlotte, attempting to soften the truth; and his doctors straddling opposing sides.

According to Janice Hadlow, author of A Royal Experiment: The Private Life of King George III, things came to a head when the king’s physician, Dr. Richard Warren, refused to emphasize the king’s improvement, leading to a confrontation with the queen.

“When Warren was asked to explain why he would not sign the contested bulletin,” he’d stated that “if a man was perfectly reasonable for 23 hours and deranged during the other hour of the 24, then he considered him in the same light as if he had no lucid intervals,” Hadlow writes. The physician added in support of his opinion that “the king had cried very much.” To which the queen responded: “If you call that being disturbed, then the whole house is disturbed.”

Indeed, the strain of having to contain and manage the monarch’s illness caused the entire royal family pain and embarrassment. When King George insisted on taking his family on vacation to Weymouth, his daughter panicked. “Oh, consider the precipice we stand upon,” she wrote. “Here we can keep a secret…but at a public water-drinking place, the thing’s impossible, and was he to expose himself there, I firmly believe we should die of it, for what we go through now is almost more than we can stand.”

As royals became more visible to the public, macabre things began to happen. During the Victorian era, the fashionable Alexandra of Denmark, Princess of Wales, suffered from a myriad of illnesses and infirmities. She handled their side effects with aplomb: She concealed a scar on her neck with a kind of jeweled dog collar, which became all the rage. When rheumatic fever struck, she was left with a charming, permanent limp, which young women began to copy. To achieve the so-called Alexandra limp, society girls bought different-heeled shoes, dragging their feet to emulate their icon.

“Some remarkably foolish things have been done in imitation of royalty,” the Dundee Courier and Argus noted contemptuously, “but this is an act which involves a spice of wickedness as well as of folly. There must be a line at which even fashionable folly may be expected to stop short.”

But during the 20th century, the most devastating case of a royal with a chronic illness occurred, which would change geopolitics. “Imperial Russia,” Robert K. Massie writes in Nicholas and Alexandra, “was toppled by a tiny defect in the body of a little boy. Hidden from public view, veiled in rumor, working from within, this unseen tragedy would change the history of Russia and the world.”

When Tsarevich Alexei Nikolaevich Romanov (also known as Alexis) was born on August 12, 1904, it seemed like a godsend to his parents, Tsar Nicholas II and Empress Alexandra. But bleeding from the navel soon made it apparent that Alexei, the couple’s only son, had hemophilia, which can be traced back in the royal families of Europe to his great-grandmother, Queen Victoria. Now the heir to the throne was in a daily battle for life.

Already in a precarious situation, with revolutionary winds swirling, Nicholas and Alexandra kept their son’s debilitating, painful condition so secret that even their four daughters’ tutor, Pierre Gilliard, was long unaware of the boy’s exact condition. “Every time he disappeared, the palace was smitten with the greatest depression,” he wrote. “My pupils’ mood was melancholy, which they tried in vain to conceal. When I asked them the cause, they replied evasively, ‘Alexis Nicolaievich is not well.’ I knew that he was prey to a disease…the nature of which no one told me.”

The public was even more in the dark. Rumors swirled: The little boy had epilepsy, tuberculosis, or had been injured by a bomb. His mother, Alexandra, also a sickly woman, was devastated by her son’s horrific suffering and became withdrawn, sullen, and under the sway of the mystic “holy man” Rasputin, who she believed could save her son.

The royal parent’s withdrawal from public life and reliance on Rasputin to ease Alexei’s agonies meant the Russian people made up stories about what was happening, arguably helping spawn the Russian Revolution and the eventual murder of the royal family in 1917—a cautionary tale for future public figures.

“A revelation of Alexis’s condition would inevitably have put new pressures on the Tsar and the monarchy,” Massie notes. “But the erection of a wall of secrecy was worse. It left the family vulnerable to every vicious rumor. It undermined the nation’s respect for the Empress and, through her, for the Tsar and the throne. Because the condition of the Tsarevich was never revealed, Russians never understood the power which Rasputin held over the Empress.”

Even in Britain, where monarchs have long been more like figureheads than absolute rulers, a royal’s body was not just one’s own. On January 20, 1936, King George V was dying of chronic bronchitis. Just before midnight, as he lay in bed straining to breathe, his doctor, Lord Bertrand Dawson, injected him with morphine and cocaine to peacefully end his life. But Lord Dawson also noted another reason he euthanized the king—so that the announcement of his death could be released “in the morning papers rather than the less appropriate evening journals.”

George V’s son, George VI, had a similarly controlled end. A heavy smoker like his father, he was diagnosed with Buerger’s disease, which affected his legs and made walking and working at his desk agonizing. But neither he nor the public were ever told he had been diagnosed with lung cancer. Even when he had surgery to remove his left lung in 1951, he was told that it was because of “structural changes.” When he died of coronary thrombosis in 1952, the public was shocked, as they had been assured he was regaining his health.

The king’s widow, Queen Elizabeth (the Queen Mother), had cancer both in the 1960s and ’80s, a fact unknown to the public until after her death. She had been notably open about her health upon one event in 1982, when she was forced to go to the hospital after choking on a fishbone. “It was only the salmon getting its own back,” she joked in a statement.

Queen Elizabeth II wasn’t one to disclose health issues publicly, and the assertions made by biographer Gyles Brandreth that she was allegedly suffering from bone cancer at the time of her death have not been confirmed by the palace. Other royals around the world have recently become more open about their struggles. Crown Princess Mette-Marit of Norway has revealed her diagnosis of chronic pulmonary fibrosis. Sarah, Duchess of York, has been open about her battles with breast cancer and skin cancer. The press has reported on a statement made by the Imperial Household Agency saying that Empress Masako of Japan has an “adjustment disorder,” and she alluded to her struggles when she opened up about her worries upon taking the crown. “Giving thought to the days ahead, I sometimes feel insecure about the extent to which I will be able to be of service to people,” she said in a statement. “But I will strive to do my best so that I can contribute to their happiness.”

It is perhaps no surprise that modern royals wish to keep their health battles as private as possible. Though the fate of their countries may not be at stake, their personal well-being is. After all, despite centuries of propaganda to the contrary, royals are only human.