The Baker Who Pretended to be King of Portugal

But who is he?" César asked. "I was coming to that," the stranger's servant replied. "Only God and he know."

The dialogue occurred in Jose Zorrilla's play about a cause célèbre of the 1590s, when Gabriel de Espinosa, reputedly a pastelier in the Castilian city of Madrigal, was hanged for impersonating the late king of Portugal. I cannot speak for God, but Gabriel seems to have reinvented himself so many times that he was uncertain of his own identity. Zorrilla brilliantly depicts his interrogation by the authorities, hinting at the parallel with Christ's evasions about his kingdom. By never admitting to kingship, Espinosa convinces his interlocutors of his regality - rather as the art dealer Joseph Duveen talked up the prices of fake paintings without ever explicitly claiming they were authentic.

Of the many fictional retellings of Gabriel's story, Zorrilla's is the best. Ruth MacKay has now given us a factual account that rivals it for sensitivity and artistry. Instead of focusing on the hackneyed "mystery" of Gabriel's identity, she headlines the far more puzzling problem of his credibility. Evidently, he did not even resemble the dead king physically. His sponsors answered objections, such as that he was too old to be the king and had the wrong colouring, by averring that his privations had aged and changed him. The case in favour of his claims was always absurd - based on the allegation that he possessed more Holland linen than a commonplace baker, or that his gait and bearing were regal, or that he was suspiciously skilful in riding, fencing and foreign languages (except, with calculated effects on his own air of mystery, Portuguese). But he had charisma or perhaps wizardry - even his pastries, according to one customer, cast a spell.

The most surprising stooge was Ana de Austria - the dead king's cousin, who was in a nunnery in Madrigal, and who seems to have got to know Gabriel when he came to sell cakes. If she accepted his royal status it was because she fell violently in love with him. She wrote him passionate letters, declaring herself his wife, in spite of the fact that he already had a common-law wife of his class, and a child, whom Doña Ana promised to treat as her own. MacKay depicts Ana convincingly as a romantically susceptible young woman who yearned to be free of the religious life and, as she put it, "do the office of a woman". Even more heartfelt, perhaps, was her orphan's longing to rediscover her lost family, especially the brother whose death she never accepted and who she hoped might reappear. Her deception seems to have sobered her, and she went on to be a model nun and successively the prioress of two of Spain's most important and aristocratic convents.

As for Fray Miguel de los Santos, who may have been the author of the plot, he probably never believed in Gabriel at all but used him as a distraction and potential scapegoat in an inextricably entangled conspiracy to eject Philip II from the throne of Portugal and install the bastard pretender, Don Antònio, Prior of Crato. Fray Miguel's detractors regarded him as a consummate fraud himself, whom "people ... took for one of the apostles, although ... they never saw him fast or eat fish". He was a consummate liar, who deepened the obscurity of Gabriel's identity by inventing a new story every time the interrogators tortured him - and so prolonging his own life.

Everyone in the conspiracy was duped by consummate acting or deluded by despair or inveigled by some imagined advantage or baffled by fear. Even Philip II, who never believed in his rival's credentials, feared that the girl who passed as (and almost certainly was) Gabriel's daughter, might be a royal foundling. The atmosphere of prophecy that surrounded "once and future" kings played a part, as, above all, did the influence of romantic fiction, which made stories as fantastic as Gabriel's seem credible. Gabriel's fictions about himself - with a lot of nonsense about how a sacred oath restrained him from declaring his kingship - were obviously modelled on quixotic literature. With deft writing and lightly borne scholarship, MacKay makes the imbroglio intelligible in historical context: the restiveness of Philip II's subjects in the 1590s, when the king's imperial project seemed to be unravelling at excessive cost to taxpayers, and the surprising mobility of Iberian society, in which people of every class could move unrestrainedly around the country, and disguise and self-reinvention were routine means of self-liberation.