‘Multiculturalism’, ‘assimilation’, ‘repatriation’ and ‘ethnic cleansing’ feature almost daily in our newspapers. So do articles and letters expressing suspicion about Muslim women wearing hijab and Muslim men plotting jihad. For all their seeming modernity, these preoccupations were also those of Spain in the sixteenth century. That period, in which Cervantes, St John of the Cross and Lope de Vega flourished and an empire was created in America, has become known as Spain’s ‘Golden Century’. But a darker epithet might be more appropriate.