Noel Malcolm, a former political columnist of The Spectator, the historian of English nonsense verse and editor of Thomas Hobbes’s Leviathan, has written a book on an arresting subject. Forbidden Desire in Early Modern Europe gives close and relentless scrutiny to male-male sexual relations in Europe, the Ottoman empire, north Africa and in such dispersed colonies and outposts as New England, Peru, Cape Town and the Dutch East Indies.

Malcolm’s interest in the subject began with his find of a cache of documents dating from 1588. These recorded the official investigation of a male couple – a trainee interpreter for Venice’s envoy in Constantinople and the envoy’s barber – who fell in love. He described this affair in an essay which he offered to the scholarly periodical Past & Present. The dogmatic, uninformed and dismissive responses of the magazine’s advisers convinced him that many historians of sexuality are self-confined in an echo chamber of mutually reinforcing, uninquisitive and conformist orthodoxy.

Forbidden Desire has been written in response to this incident. It is a book of startling originality and depth. The abundance of Malcolm’s archival research, the range of languages and the geographical diversity of his material are stupendous. Only the Orthodox Slav world is omitted for lack of reliable evidence. No one else has had the temerity or linguistic skills to attempt so comprehensive a survey.

Time and again Malcolm detects western historians of sexuality in crass mistakes, wilful exaggeration, lubricious pipe dreams, distorted quotes, abuse of evidence and deliberate obscurity. His relentless precision and crystalline prose should rally historians of nuance and scruple to confront the propagandist sham-scholars who prefer identity-driven theory to hard, clear evidence.

The prevalence of man-boy sexual relations in the ancient world and Mediterranean region, which had been attested for centuries, started to be denied in the late 20th century. Commentators such as Edward Said decried such talk as oppressive and racist Orientalism. Other historians dismissed western European descriptions of Ottoman sodomy as ‘sexual fantasies’, and by other terms intended to degrade them from sober facts.

‘Evidence is evidence,’ Malcolm insists. He finds the quantity, consistency and credibility of such evidence from westerners to be undeniable. More than that, he consults Ottoman sources on Ottoman sexual conduct, as monolingual or bilingual historians have never done, and finds similar reports of the propositions and inducements that culminated in the exchange of bodily fluids.

The prevalence of male-male sexual relations in the pre-modern Arab east and in early modern Ottoman society was attested by romances, love poetry, biographies, homilies, juridical records and masculine socialising. Almost always the object of love or desire was a comely youth whose downy cheeks had no growth of stubble.

Malcolm’s voluminous researches reveal wide differences between southern and northern Europe in the practice of, and attitudes to, male-male sexual relations. Young adult southerners in early modern Europe had more limited opportunities for marriage than their northern equivalents, he shows. There was lower sexual availability of women. Male-male contacts were an expedient substitute, and not unthinkable in early modern southern Europe with its likely continuities with the age-differentiated man-boy sexual habits of the ancient Mediterranean.

In 15th-century Florence, for example, a man might seize the hat of a boy in the street and hold it ransom until the boy had complied with the aggressor’s sexual demands. Most Florentine men who had sex with boys during their early adulthood also sought equivalent experiences with women, and eventually forsook same-sex relations for the settled experience of the marital bed. These men were unmarked by any special identity just because they grabbed passing chances to enjoy male-male sexual acts. Men who had sex with other males had no commonality with women who had sex with females.

The doctrinaire French historian Michel Foucault described these man-boy relations with fair accuracy almost half a century ago. But he proceeded to distinguish these pre-modern ‘sodomites’ from the 19th-century men who, by performing sexual acts with other men, had the social, cultural and pathological concepts of the ‘homosexual’ attached to them. These concepts attributed effeminacy, treachery and emotional immaturity to the men, who became stigmatised as pansies, nancies, fruitflies and the rest.

Foucault ascribed the division between ‘sodomites’ and ‘homosexuals’ to Enlightenment oppression. Orderliness, regulation and the surveillance of capitalist discipline seemed to him to penalise vital life forces. Describing a personal epiphany of his own, Foucault said: ‘I know that this is not true, but it is the truth.’ In this sentence he gave the creed of a new generation of post-modern anti-historians toying with the past. His tales of labels forcibly pinned by authority on minorities are the basis of much 21st-century identity politics.

Almost always the object of love or desire was a comely youth whose downy cheeks had no stubble

Foucault’s followers moved the emergence of the homosexual identity from mid-19th-century oppressors to the period around 1700. Malcolm demurs. Long before then, he shows, there were adult men in southern Europe and many more in northern Europe who were sexually passive in sodomy, found women’s bodies fearsome or distasteful and were inveterate in their distinctiveness.

Neither the abundance of evidence from southern Europe on male-male sexual relations nor its content is matched in northern European kingdoms, including England. Religious prohibitions, social attitudes, judicial documents and literary culture vary on either side of the 45th Parallel in Europe. Militant historians of identity, however, have twisted evidence in order to support specious arguments about authoritarianism, institutional mismanagement, technocratic surveillance and victimhood.

Malcolm trounces a professor of history from Arizona, calling himself an anti-historian, who wrote a preposterous fact-free exercise in wishful thinking about sodomitical English sea-rovers in the 17th-century Caribbean. He lambasts those who snatch a phrase from a 17th-century text and misapply it to make a category mistake or to use it in justification of a grandiose, tendentious special pleading about the origins of identity politics.

There are some high jinks, too. It is pleasing to picture the scene in Tangiers when an irritable Arab passer-by espied semi-naked young Englishmen chasing one another with buckets of water and exchanging playful spanks. Intriguing, too, to conjure a transvestite named John/Eleanor, who sold sex to Oxford students in the 1390s. I like the Protestant notion that a pope in Rome had authorised sodomy in the three hottest months of the year. Best of all, Malcolm recounts a tale (published in Valencia in 1519) about the accidental impaling of a demon on the erection of a cowherd who had been massaging his aching loins with butter. It ends with the sorry fiend ‘mending his arse’ in Hell.