On the first day of Francisco de San Antonio's trial before the Spanish Inquisition in Toledo in 1625, his interrogators asked him about his parentage. His real name, he stated, was Abram Ruben, and he had been born in Fez of Jewish parents. How then, Inquisitors wanted to know, had he become a Christian convert? Why had a Hebrew alphabet been found in his possession? And what was his business at the Court in Madrid? He was asked, according to his...