Mistress of the Monarchy

Further Thoughts on the Causes of the Deaths of John of Gaunt and Katherine Swynford


 In Chapter 9, I discuss the theory that John of Gaunt suffered from, and died of, a venereal disease, and suggested the possibility of his having contracted gonorrhea, although I did stress that the evidence is, of course, inconclusive. Since this book was published, I have been fortunate to have the benefit of the medical opinions of two experts, which may throw some light on the Duke’s final illness, and Katherine Swynford’s death, and are an essential addition to this book. 

If we believe the evidence for a disease affecting the sexual organs, then we should perhaps look beyond the assumption that it was venereal. Dr. Susanne Dyby is a biologist, and she thinks it unlikely that John of Gaunt suffered from gonorrhea; certainly it is very rare to die from it, for it is usually relatively benign as diseases go. Dr. Cynthia Wolfe has confirmed that gonorrhea, and today’s most common type of chlamydia, do not cause “putrefaction of the genitals and body,” as Gascoigne described. They do cause rather mild discomfort (if any), some pus from the urethra or vagina, and infertility, but never ulceration or putrefaction outside the body. The symptoms, if any, tend to show up within a month, and sexual contacts are almost always also infected. So it is almost certain that neither gonorrhea nor chlamydia was the cause of John’s diseased groin. 

Dr. Wolfe believes that I could be right in speculating that John of Gaunt had a venereal disease, or that he could have contracted a rare type of chlamydia trachomatis disease called lymphogranuloma venereum, which does cause swelling of inguinal lymph nodes, ulcerations, skin breakdown and putrefaction, is slow in onset, and is not so easily transmitted, thus accounting for the fact that Katherine did not seem to suffer. Dr. Dyby thinks that, after their separation in 1381, it is certainly possible that John contracted gonorrhea, and that, when the couple reunited, this could have caused sterility in Katherine, sterility being a common by- product of sexually transmitted diseases. Even so, it is unlikely that an STD killed either John or Katherine, given that syphilis had not yet arrived in Europe and that the Duke’s mental state was clear at the very end. 

Dr. Dyby believes it far more credible that he contracted malaria in Aquitaine, in the marshes and the mosquito- ridden summers of southwest France. The intermittent high fevers that he suffered might suggest this diagnosis. Both experts suggest that John could have had a cancer that was slowgrowing and destructive, and Dr. Dyby offers the convincing theory that he suffered from prostate cancer, which could have been responsible for the putrefying—and possibly stinking—genitals that John had allegedly displayed to Richard II. It can also cause many other ghastly effects on the body, if the disease is allowed to run its course over a long time without any effective treatment, as must invariably have been the case in medieval times. It would not be surprising if the Duke’s contemporaries concluded that such a disease was the consequence of fornication. 

Dr. Dyby also mentions another malady that can cause kidney failure, gangrene, blindness, as well as other symptoms: by- proddiabetes. Aristocrats at that time certainly had the lifestyle to induce it, not to mention all the lead and mercury and woodsmoke to which they were exposed. Therefore, we should not discount the possibility that John of Gaunt was an untreated diabetic. 

As Dr. Dyby points out, two factors militate against accepting Gascoigne’s account. Apart from the documentation of John’s extramarital affairs, there is no evidence dating from his lifetime or soon afterward, to suggest that his final illness was a venereal disease. Would Richard II, who possibly had the callousness to throw unpaid bills on Gaunt’s deathbed, have refrained from comment at what he had been shown, or from making political capital out of the fact that the Duke was dying from his “sinfulness,” especially when he had the chance to discredit John with a view to seizing his estates? Then there is the Duke’s request to leave his corpse for forty days in state, above ground; if he was so badly diseased, would he have inflicted such a horrific charge on his widow and family? 

Dr. Dyby suggests that Katherine Swynford might have died of tuberculosis, given that Kettlethorpe was moated, situated on a river, and humid. Rheumatic fever was also very common in those days, and can have a nasty affect on the heart. This might account for Katherine’s frailty, and thus her absence from the records, in her declining years. 

The evidence for John of Gaunt’s final illness is still inconclusive, of course, and we can only speculate as to the cause of Katherine’s death, but these theories are an invaluable contribution to the debate. 

I am indebted to Dr. Susanne Dyby and to Dr. Cynthia Wolfe for supplying much of this information, and for so generously giving me permission to include it in the book.