The myth of 8 million hidden Jews in Spain

The myth of 8 million Spaniards of Jewish origin

How many Spaniards carry Sephardic ancestry without knowing it? The figure that circulates — eight million Bnei Anusim, conversos or descendants of Jews — sounds like a historical revelation and is, above all, an exercise in creative arithmetic. The starting point is an estimate: for the 14th century, nearly 500,000 Jews are said to have lived in the peninsula. In 1492, with the expulsion decree, 100,000 are said to have left. With those figures, someone subtracts and concludes that the rest stayed behind, converted, and left a massive genetic imprint. The problem is that the numbers simply do not add up.

Why the aljama tax records are no census

Medieval records of the Jewish communities were tax assessment books, not population censuses. They counted heads of household — adult male taxpayers — and tended to be inflated in order to negotiate tax levies with the crown. Turning those numbers into a total population requires multiplying by household coefficients that nobody knows with precision. Getting to half a million from there is a considerable leap.

The second figure, the 100,000 expelled in 1492, does not come from any official document either. It is oral tradition repeated for centuries. Some historians reduce it by half or more. If the exodus was smaller, the number of conversos who stayed also shrinks, and with it the entire pyramid.

Genetics cannot tell a fourth-generation converso apart

Moving onto biological ground adds another problem. The Sephardic genetic signature overlaps with the general Mediterranean one: sharing markers with populations from North Africa or the Near East does not make anyone a direct descendant of an expelled family. Four generations of mixing dilute any identifiable trace. What some DNA kits sell as certainty is, at best, a statistical probability.

Add to that the surname industry. Lists of thousands of surnames presented as Sephardic circulate that, in practice, include half of Spain. Toponymic surnames, occupational names or plain coincidence inflate a catalogue that is sold as documentary proof and is not.

From dubious data to pointing fingers at faces and surnames

The conversation soon drifted into physiognomy and personal names. Some claim that certain facial antiestéticatures betray Jewish ancestry in Castilians, Catalans, Valencians, Andalusians or Extremadurans, and others outright assert that Semitic populations would have damaged the beauty of the places where they settled. It is the old logic of the 16th-century treatise writer recycled with forum vocabulary: classifying by appearance and seeking origins in a neighbour's face.

The next step is the list of suspects. Names of politicians, businessmen, actors and chefs are cited as proof of an alleged infiltration, and compound surnames are dredged up to hint at lineages. All of it without a single document, without an archive, without a birth record. Suspicion replaces the data, and the data, when it appears, refutes it.

What is left of the eight million calculation

What remains is a round, striking figure with no documentary basis. What remains is the temptation to turn medieval history into a purity test and genetics into a classification tool. And above all, what remains is a fundamental misunderstanding: the fact that mixing is the norm in the peninsula proves no theory, because mixing is the norm in any Mediterranean population.

Eight million Spaniards partially of Jewish origin. Or none at all. The range is so wide that the headline holds itself up. And it keeps circulating.