They were driven from the Iberian Peninsula in one of Europe’s notorious purges. But more than 500 years after the last Jews and Muslims were “ethnicly cleansed” from Spain and Portugal their ancestors are thriving.

Spanish film starlet Penélope Cruz or the Oscar-winning director Pedro Almodóvar might originally be descended from Jewish stock. Equally, the tempestuous Portuguese football manager José Mourinho or the Nobel prize-winning novelist José Saramago may well have had Muslim ancestors.

These intriguing genealogical possibilities arose after a study found evidence that 19.8 per cent of today’s Spaniards and Portuguese were originally Sephardic Jews. Another 10.6 per cent have a genetic make-up that suggests they were descended from Muslims.

The study found that the genetic signatures of Spaniards and the Portuguese indicate evidence of mass conversions of Sephardic Jews and Muslims to Catholicism from the 15th century.

In 1492 King Ferdinand II of Aragon and Queen Isabella I of Castile completed the Reconquista (Recapturing) of the Iberian Peninsula by Catholic forces from the Muslim monarchs who had held what is today Spain and Portugal since 711.

The Catholic monarchs then forced Jews and Muslims to convert to Catholicism or go into exile. Despite their best efforts to “ethnicly cleanse” the Iberian Peninsula, the genetic fingerprint of Jews and Muslims remains until today.

The study, based on an analysis of Y chromosomes, was conducted by geneticists Mark Jobling, of the University of Leicester, and Francesc Calafell, of the Pompeu Fabra University in Barcelona. They developed a Y chromosome signature for Sephardic men by studying Sephardic Jewish communities in places to which Jews migrated after being expelled from Spain. They also mapped the Y chromosomes of the Arab and Berber army that invaded Spain in AD711 from data on people living in Morocco and the Western Sahara.

The study, published in the American Journal of Human Genetics, showed a high level of conversion among Jews. The Y chromosome remains unchanged from father to son so the proportions of Sephardic and Moorish ancestry detected in the present population is probably the same as those after the 1492 expulsions.

The scientists were able to pinpoint parts of Spain where there were more or fewer Sephardic Jews and Muslims than others. So, in Castilla la Mancha, where Almodóvar was born, there is a slightly higher proportion of Sephardic Jews than in some other areas, raising the possibility that the director of Volver and All About My Mothermight have some Jewish blood running through his veins.

The number of Jews found in Catalonia was very low in comparison with other regions, meaning that the chances that writer Carlos Ruiz Zafón, author of the bestselling The Shadow of the Wind, is from Jewish ancestry are negligible.

Dr Calafell said that the study shed light on some of the darker passages of Spanish history.

“One aspect of this study that is sad is the low number of people with Jewish links in Catalonia which means most were wiped out in the pogroms in the 14th century,” he said.

The study, which estimates the number of Jews and Moors in the population, was based on tests on 1,140 people across Portugal and Spain.

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