IRONY COMES EASY to the dead, who are blessed with both hindsight and foresight; or at least to those of the dead who take an interest. Christopher Columbus, from his perch in the afterlife, has cast a critical eye on his own career, on his contemporaries, his biographers, and the modern world. He is fortunate to have found, in Stephen Marlowe, a ghostwriter of awesome competence and stamina.

Columbus has a motto: When in doubt, move. He has a theory too, that ‘history is mostly a toss of the dice.’ In fact, if Holy Week and Passover had not coincided in the year of his birth, ‘someone else would have become the most fa mous man in the world.’ Modesty is not amongst his attributes. ‘I was’, he tells us, in the light of later events, ‘the worst thing that happened to Italy until Mussolini.’

He was not born in Italy, but in Spain, to a family of ‘New Christians’ – which is to say that he has a Jewish momma. ‘That the Messiah had already come she found disappointing. There was nothing to look forward to.’ He has an ugly brother, Barto, whose warts drop off the morning after he has slept with a princess. He loses sight of his family early in life, but during his extensive travels their paths cross and recross in the most surprising ways. There is, very nearly, a surprise on every page.

His first career break is as Roderigo Borgia’s food taster; then it gets more risky. He leaves Italy to avoid contract killers, and undertakes his first sea-voyage: ‘I never learned the captain’s name. Call him Captain Catastrophe.’ He is in many ways a reluctant hero; when people say to him ‘I’m looking for a partner, an experienced mariner like yourself,’ he tends to say, ‘Sorry, I have more important business.’

Ten years go by, as a voyager on the earth ‘s northern rim, wondering why Greenland has disappeared; the fifteenth century was like that. There are two years as a spy in Granada; and incidentally, he marries Torquemada’s cousin. But the Great Venture is always ahead of him – the plan to reach the east by sailing west. ‘Am I’, he asks, ‘any less monomaniacal than Ahab? Isn’t the fabled East my great white whale?’

And when he finally arrives on the coral shores of the New World, he contemplates an epigram: ‘One small step for a Christian, one giant step for mankind.’ But Indian eyes are watching from the woods. H e has other languages at his command, besides the streetwise Americanese in which he has dictated this posthumous memoir. He tries Latin, he tries Aramaic; but his men already have gold fever, that most deadly of tropical diseases – and the great non-communication has begun.

Although he lambasts the myth of the noble savage, Columbus is always sensible that the drawbacks of exploration must be weighed against its rewards; premarital sex, he tells us was the rule in the Iberian peninsula, until his crew discovered syphilis, which put a damper on things. He is trenchant and often enjoyably crude about national foibles; his narrative of his stay in England compromises between ‘respect for the truth and respect for the squeamish.’ In the end it is the ‘map of time’ which preoccupies him, and his resolute way with anachronism makes him a knowing cartographer. His narrative never flags, his ingenuity never falters, and his jokes never pall. He has written a book which he could have used in his lifetime; if you were shipwrecked with these memoirs, you wouldn’t want to be rescued until you’d finished them.