Poison plot is hard to swallow

Roderigo Lopez was executed at Tyburn on June 7 1594, convicted of plotting to murder Elizabeth I but pleading his innocence. He was a Portuguese Jew by birth, a convert (more or less) to Christianity, and had come to London in 1559 to escape the Inquisition. First, he was a physician at St Bartholomew's Hospital, London, but later he acquired a society practice, treating noblemen, courtiers and politicians - in 1581 he was appointed physician to the queen herself.

Had he really planned to kill his best patient? Under threat of torture, Lopez claimed he had joined a plot to poison Elizabeth, but only to foil it. The queen would not swallow the doctored medicine, he said: "I knew Her Majesty never doth use to take any syrup." It was a thin defence, and it failed.

How did Lopez get himself into such a fatal mess? It is sometimes suggested that he was an innocent victim of the earl of Essex's determination to prove himself a serious statesman, revealing an international conspiracy that stretched into the queen's privy chamber. Or was he a minor casualty of factional conflict between Essex and the Cecils, a Cecil supporter crushed by a rival political machine? Perhaps he was just too clever by half, too eager to be in the thick of things and taking too many risks.

Lopez had a second career, as a spy and counter-spy, through his connections in the Iberian Jewish diaspora. He had begun as an ambassador for the Portuguese pretender, Don Antonio, and had served Sir Francis Walsingham. Eventually, he was working for almost everyone: Essex as well as the Cecils, Spain as well as England - or, at least, he claimed to work for them and took their rewards.

Dominic Green suggests Lopez was used by the Cecils to spy on Antonio Perez, a Spanish traitor and ally of Essex - but Lopez agreed to help murder Perez for King Philip II of Spain. When Lopez was accused of treason by Essex, the Cecils covered their tracks by framing Lopez themselves.

Evidence was doctored, confessions were forced and a plot to shoot an exiled Spaniard was turned into a plot to poison the queen of England. For three months Elizabeth would not sign the execution warrant, but, with Essex and the Cecils against him, Lopez had to go.

Green unravels a lot of the detail and tells an interesting and plausible tale. Presumably he wants to emulate John Bossy, drawing best-selling spy stories from Elizabethan archives. But Bossy does it better: he has a cooler head and a sparser style, and is an Elizabethan scholar.

Green's bibliography misses most of the useful work on late-Tudor politics; his transcriptions are often inaccurate; and there are inconsistencies and minor errors of detail. The text is overwritten: packed with outrageous similes, metaphors and flights of literary fancy, melodramatic and verbose, and high on inventive colour and atmosphere. Oh, and there's young Shakespeare: Lopez knew Essex, Essex knew Southampton, Southampton (perhaps) knew Shakespeare, surely Shakespeare knew Lopez? And Shylock was a Jew. Nuff said?

Christopher Haigh is lecturer in modern history, University of Oxford.