The autopsy of King Charles II, performed shortly after his death on February 6, 1685, revealed extensive damage inside his brain, including a large volume of blood and fluid in the ventricles, alongside signs of long-term kidney disease. These findings, recorded by the royal physicians, have fueled centuries of medical detective work. What killed the “Merry Monarch” remains genuinely debated, partly because the autopsy report sits at the intersection of seventeenth-century medicine, modern neurology, and the grim reality that his doctors spent his final five days administering dozens of treatments that may have hastened his end.
The Collapse on February 2, 1685
Charles II was fifty-four years old when he collapsed without warning on a Monday morning while being shaved in his bedchamber at Whitehall Palace. Witnesses described a sudden cry, followed by a violent convulsion. He fell unconscious and appeared, to the horrified courtiers present, to be dying on the spot. One of his physicians, Edmund King, happened to be nearby and performed an emergency bloodletting almost immediately, drawing roughly a pint of blood from a vein in the king’s arm before any formal consultation had taken place. Charles regained a degree of consciousness after the bleeding, but he was confused, intermittently convulsing, and clearly in serious distress.
Over the next five days, a rotating team of more than a dozen physicians attended the king around the clock. Their collective response to his worsening condition was to try everything they had. The sheer volume of interventions Charles endured between his collapse and his death is one of the most frequently cited case studies in the history of medicine, often used to illustrate just how aggressive and misguided pre-modern therapeutics could be.
Five Days of Treatment
The catalog of remedies administered to Charles II during his final illness reads like a catalog of seventeenth-century pharmacology. He was bled repeatedly, losing large quantities of blood over several sessions. Cupping glasses were applied to his shoulders. His scalp was shaved and blistered with cantharides, a caustic preparation derived from blister beetles, intended to draw “morbid humors” away from the brain. He received multiple enemas, some containing antimony compounds, and was dosed with purgatives to induce vomiting and bowel evacuation.
Among the more unusual treatments, Charles was given drops of “spirit of human skull,” a distillation made from pulverized cranial bone, and was encouraged to drink from a cup fashioned from a skull in the hope of a cure.1The Lancet. Human skulls as medicine He was also given bezoar stone dissolved in liquid, Jesuit’s bark (an early form of quinine), herbal infusions, and preparations containing pearl and crab’s eyes. None of these treatments succeeded. By Friday, February 6, Charles was slipping in and out of consciousness. He apologized to those around him for “being such an unconscionable time dying,” offered a last request that his mistresses be looked after, and died that morning.
What the Autopsy Found
The post-mortem examination was carried out by the royal physicians, with Dr. Thomas Short later summarizing the findings. The most striking discovery was inside the skull. When the physicians opened the cranium, they found an extraordinary quantity of serous fluid and blood filling the ventricles of the brain. The brain tissue itself was described as largely intact and of a normal appearance, but the accumulation of fluid pointed to a catastrophic event within the cranial cavity. Modern readers of the report generally interpret this as evidence of a massive intracerebral or intraventricular hemorrhage, essentially a severe stroke.
Beyond the brain, the autopsy documented other abnormalities. The kidneys drew particular attention. They were described as having a granular appearance and containing what appeared to be damage consistent with chronic disease. The heart was found to be large and firm, though without obvious structural defects visible to seventeenth-century eyes. The lungs showed some pleural adhesions but were otherwise unremarkable. The liver and spleen were noted without major comment.
For the physicians present, the findings confirmed their suspicion that the king’s brain had been the seat of his illness. But the kidney findings are what have most interested later medical commentators, because granular kidneys are a hallmark of chronic nephritis, a long-term inflammatory condition of the kidneys. That detail suggests Charles may have been quietly ill for some time before his dramatic collapse.
The Leading Modern Diagnoses
Physicians and historians who have revisited Charles II’s case over the past century and a half have proposed several diagnoses. None can be proven definitively, but they fall into a few main camps.
The most straightforward interpretation is that Charles died of a stroke. The blood and fluid in the brain ventricles point to an intracerebral hemorrhage, and his sudden collapse with convulsions fits the clinical picture. The granular kidneys suggest he had chronic kidney disease, which would have driven up his blood pressure over time, raising the risk of exactly this kind of hemorrhagic event. High blood pressure remains the leading risk factor for this type of stroke today. Under this reading, the immediate cause of death was the brain hemorrhage, and the underlying cause was kidney-driven hypertension that had been building for years.
A second theory implicates uremia, the toxic buildup of waste products that failing kidneys can no longer filter. If Charles’s kidneys had deteriorated to the point of near-failure, uremic encephalopathy could explain both the seizures and the altered mental state. The brain hemorrhage, in this framework, would be a consequence of the same kidney failure rather than an independent event. Uremia can cause bleeding complications, making this scenario medically plausible.
A third and more dramatic proposal centers on mercury poisoning. Charles was an enthusiastic amateur chemist who maintained a private laboratory at Whitehall, where he conducted experiments with mercury and other volatile substances. Chronic mercury exposure can damage the kidneys, cause neurological deterioration, and in severe cases trigger convulsions and death. Proponents of this theory argue that the autopsy findings, particularly the combination of brain and kidney damage, fit a pattern of long-term mercury toxicity. The king’s well-documented fascination with chemical experiments gives the theory a biographical foothold that the other diagnoses lack.
A less commonly cited but still circulated suggestion is that Charles had some form of chronic infection or abscess that eventually reached the brain. This accounts poorly for the autopsy findings, though, which did not describe purulent material or obvious infection in the cranial cavity.
Why No Single Diagnosis Has Won
The core problem with retrospective diagnosis, especially one based on a seventeenth-century autopsy, is that the original observers were working within a medical framework completely different from our own. The humoral theory of disease shaped not just how physicians treated patients but what they looked for and how they described what they saw. When Charles’s doctors reported fluid in the brain, they were interpreting it through a lens that understood disease as an imbalance of bodily fluids. Their descriptions are filtered through that lens, and we cannot always be sure what a modern pathologist would have seen on the same table.
Scholars who study the history of disease have emphasized just how treacherous this kind of backward-looking diagnosis can be. One analysis of the practice warned that it is often “just not possible to come to a modern biological diagnosis for many past disease episodes,” because historical texts record what their authors considered relevant, not what a modern clinician would want to know.2International Journal of Paleopathology. Retrospective diagnosis and the use of historical texts for investigating disease in the past Others have urged historians to ask whether applying modern diagnostic labels to pre-modern illness accounts genuinely improves historical understanding or simply distorts it.3Studies in ancient medicine. Approaches to the History of Patients: From the Ancient World to Early Modern Europe
In Charles’s case, we lack tissue samples, blood work, imaging, or any of the tools that would let a modern doctor distinguish between a hemorrhagic stroke caused by hypertension, uremic encephalopathy with secondary hemorrhage, and chronic mercury poisoning with end-stage renal failure. All three diagnoses are consistent with the surviving evidence. The autopsy report is detailed by the standards of its time but tantalizingly incomplete by ours.
Did the Treatments Kill Him?
A question that inevitably follows any account of Charles II’s final days is whether the aggressive medical intervention contributed to his death. The short answer is: almost certainly yes, though by how much is impossible to quantify. The repeated bloodlettings alone would have worsened his condition. A man in the throes of a brain hemorrhage or acute kidney failure would have been profoundly debilitated by the loss of several pints of blood over five days. The antimony-based emetics and purgatives caused violent vomiting and diarrhea, leading to dehydration and electrolyte derangement at a time when his body was already failing. The blistering agents applied to his scalp caused pain and tissue damage without any plausible therapeutic benefit.
In fairness, his physicians were doing everything their training told them to do. Bloodletting was standard practice for nearly any acute illness, and the logic of humoral medicine demanded that toxins be drawn out of the body by any available route. The use of skull-based remedies, while bizarre to modern eyes, reflected a genuine pharmacological tradition that persisted well into the eighteenth century. The physicians were not incompetent by the standards of their era. They were simply operating within a medical paradigm that, in this instance, made a dying man’s final days far more miserable than they needed to be.
Mercury and the Royal Laboratory
The mercury-poisoning hypothesis deserves separate attention because it connects Charles II’s death to one of his most distinctive personal habits. Charles maintained a laboratory in Whitehall where he personally conducted chemical experiments, particularly involving mercury. This was not unusual for a man of his era and station. The late seventeenth century was a period of intense interest in alchemy and early chemistry, and wealthy gentlemen across Europe pursued similar hobbies. But mercury is extraordinarily dangerous. It accumulates in the body over time, with chronic exposure causing damage to the kidneys, nervous system, and gastrointestinal tract.
The symptoms of chronic mercury poisoning include tremor, irritability, memory problems, and kidney inflammation. Over years, kidney damage from mercury exposure can progress to the granular nephritis described in Charles’s autopsy. If Charles had been handling and heating mercury regularly in his laboratory for years or decades, the cumulative dose could have been substantial. There is no record of anyone monitoring his exposure or suggesting he take precautions, and seventeenth-century experimenters routinely handled toxic substances with bare hands and in poorly ventilated rooms.
The weakness of the mercury theory is that it is circumstantial. We know Charles had a lab and worked with mercury. We know his autopsy showed kidney and brain damage consistent with mercury poisoning. But kidney disease and brain hemorrhage are also consistent with simple hypertension, and there is no way to test his preserved remains for mercury levels. The theory is plausible and narratively compelling, but it cannot be confirmed or excluded with the available evidence.
The Political Dimensions of a Royal Death
The autopsy of Charles II did not take place in a vacuum. It occurred at one of the most politically charged moments in English history. Charles had no legitimate heir, and his brother James, Duke of York, was a Catholic convert in a staunchly Protestant country. There had been repeated attempts during Charles’s reign to exclude James from the line of succession, and the question of whether Charles himself was secretly Catholic had dogged him for years.
On his deathbed, Charles received last rites from a Catholic priest, Father John Huddleston, who was smuggled into the royal bedchamber through a back passage. Whether this represented a genuine conversion or a confused dying man’s acquiescence to the people around him has been debated ever since. The autopsy mattered politically because it could either confirm or cast doubt on the official narrative of the king’s death. If Charles had been poisoned, for instance, that would have raised explosive questions about who stood to benefit. The physicians’ findings of natural disease, particularly the brain hemorrhage, served the interests of a smooth succession by establishing that the king had died of God’s will rather than human malice.
Some contemporaries were not convinced. Rumors of poisoning circulated in the weeks and months after Charles’s death, with suspicion falling variously on James’s allies, on Charles’s own court, and on foreign agents. None of these rumors were ever substantiated, and the autopsy evidence, such as it is, supports a natural death. But the political context meant the autopsy was never purely a medical exercise. It was also a political document, intended to reassure a nervous kingdom that its king had not been murdered.
What Survives of Charles II’s Remains
Unlike some English monarchs whose remains have been exhumed and examined with modern techniques, Charles II’s body has not been subjected to contemporary forensic analysis. He was buried in Westminster Abbey, and there has been no modern effort to open his vault for scientific investigation. This means the autopsy report from 1685 remains the only direct physical evidence of his condition at death. Any modern diagnosis must rely on the words his physicians chose, interpreted across a gap of more than three centuries of medical progress.
If his remains were ever examined using modern methods, researchers could potentially test for mercury and other heavy metals in bone and hair samples, look for signs of chronic kidney disease in preserved tissue, and perhaps settle the question of whether a single diagnosis or a combination of factors ended his life. Whether such an examination will ever be permitted is another matter. The exhumation of royal remains is an extremely sensitive issue in Britain, and there is no indication that such a study has been proposed or would be welcomed. For now, the 1685 autopsy is all we have, and the debate over what killed Charles II will likely continue as an exercise in historical inference rather than forensic certainty.