Resurfacing from the Aeon archive, Katherine Harvey’s 2018 essay marked her first in-depth exploration of medieval sex—a journey that later blossomed into her book, The Fires of Lust. This upfront piece studies medieval Europe’s startlingly frank approach to the dangers of sex. Too much sex was dangerous, and too little sex could outright kill you. Quite the ride!

Medieval physicians saw too much sex as a real medical concern. Conventional wisdom held that several noblemen died of sexual excess. John of Gaunt, the 14th-century first duke of Lancaster, allegedly ‘died of putrefaction of his genitals and body, caused by the frequenting of women, for he was a great fornicator’. Today, his symptoms would suggest venereal disease, but his contemporaries would probably have seen parallels with the case of Ralph, count of Vermandois. This 12th-century French nobleman had recently married his third wife when he fell seriously ill. During his convalescence, he was advised by his physician that he must abstain from intercourse, but disregarded this warning. When the doctor detected from Ralph’s urine that he had done so, he advised him to set his house in order, for he would be dead within three days – a prognosis that proved to be accurate.

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