The Papal Decree That Doomed Medieval Cats

In 1233, Pope Gregory IX issued a papal bull known as Vox in Rama. It described heretics kissing a black cat “under the tail” as part of their rites, claimed that demonic figures appeared in cat‑like form, and framed cats — especially black ones — as bound up with satanic ritual and the Devil’s presence.

Cats already carried symbolic baggage in medieval Europe, but Vox in Rama gave religious authority to the idea that they were instruments of darkness.

Medieval communities took this seriously. Cats were persecuted and killed across parts of Europe: thrown into bonfires on feast days, hurled from towers, beaten, drowned and burned in public entertainments. Black cats were especially targeted, but suspicion often fell on cats of any colour.

For decades, in many regions, the cat population was reduced and their status as household protectors was undermined.

Then the rats came. Then the fleas came. Then the plague came.

The horror: rats, fleas, people The Black Death reached Europe in 1347, carried on trade ships to ports such as Messina. Sailors disembarked covered in dark swellings. Many were already dying. Within a few years, the epidemic had swept across much of Europe, killing somewhere between a third and perhaps over half of the population in affected regions.

The bacterium responsible, Yersinia pestis, was transmitted by fleas that often lived on black rats. Those rats travelled on ships and carts, nested in granaries and houses, and fed wherever humans stored or dropped food.

The one domestic animal best suited to keeping rat numbers down — the cat — had been relentlessly demonised in religious and popular culture.

Here the historical debate begins. Some scholars argue that cat numbers may have recovered in many places before 1347, or that other ecological factors mattered more than feline persecution. Others point out that deep cultural suspicion of cats and their association with witchcraft and heresy discouraged people from keeping them, especially in towns, and made systematic rat control less likely.

What is not disputed is the broad outline: for generations before the Black Death, powerful voices had taught that cats were spiritually dangerous. The animals most useful in controlling rodent populations were treated as problems rather than solutions.

Whether the papal bull “caused” the plague is something no historian can prove. Whether it helped shape a world in which rats and their fleas thrived is a question that lingers.

The idea of cats as demonic companions persisted long after the first wave of plague. During witch trials in the 15th to 17th centuries, cats — especially black ones — were seen as “familiars”, animal helpers to witches. Owning a black cat could be taken as supporting evidence of witchcraft. In some trials, cats were killed alongside the accused.

The modern relic: superstition on four legs The superstition is still with us. In much of Western culture, a black cat crossing your path is said to bring bad luck. Popular Halloween imagery routinely pairs black cats with witches’ hats and broomsticks.

Animal shelters report that black cats often stay longer before adoption than lighter‑coloured cats, a phenomenon sometimes called “black cat syndrome”. Some rescues pause black‑cat adoptions around Halloween out of concern that they will be mistreated as props.

Most people who hesitate around black cats have never heard of Vox in Rama and have never burned a cat in a bonfire. But the symbolic association set down in a papal document nearly 800 years ago, reinforced by centuries of folklore and witch‑trial panic, still shapes how we see a particular colour of animal.

The cats burned in medieval squares are gone. The rats they might have hunted are gone. The plague that ravaged Europe is long over.

The superstition that helped make cats suspect is still crossing the street in front of you.

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