The Guadalquivir River makes a dramatic loop southward as it passes the city of Córdoba on its way to the Atlantic. A Roman bridge connects the two banks; on the right bank is the magnificent Mezquita, the great mosque of Córdoba.
Every schoolboy knows (as Macaulay was fond of writing) that the Moors invaded Spain in 711 and that Córdoba, a city of Muslims and Christians and Jews, grew into a great medieval center of world culture in the ninth and tenth centuries, the home of Maimonides and Averroës.
Given today’s tensions between the West and Islam, the city’s past may seem to be one of those rare moments in history when people accepted their religious and social differences and got on with their lives in a place of beauty, diversity, and real understanding. In other words, a moment from which we can learn something.
Yet between AD 850 and 859, while the builders of the mosque were fashioning Roman and Visigothic stone into their Islamic masterpiece, forty-eight Christians, both men and women, were beheaded, their bodies thrown into the Guadalquivir. Their crime was to declare themselves Christians, and some defamed the Prophet Muhammad and his faith. Most of the martyrs were priests and monks, and their names wonderfully suggest the time and the place: Perfectus, Alodia, Regollius, Servus Dei, Benildis, Pomposa, Abundias, Salomon, Eulogius. Some came from...