In the unenlightened Britain of the Middle Ages, the Church was hard at work cementing the foundations for centuries of sexual double-standards and miserabilism.

      Its moral leaders could not actually ban sex – they had to be practical, and intercourse was the only reliable way that mere mortals could fulfil God’s command to go forth and multiply. Nevertheless, the clergy shared St Paul and St Augustine’s wholehearted distaste for this undignified and bestial act – especially if anyone appeared to be having fun while performing it. Lust was a tool of the serpent of Satan, which turned the natural and sinless act of marital baby-making into something damnably hellish. Enjoying marital sex (rather than only putting up with it) constituted a venial sin. Adultery or fornication, moreover, constituted a mortal sin. Celibacy was the safest recommended route to heaven.

      So when the local peasants sought advice on the physical side of marriage, the clergy were less than encouraging. One of the Church’s authoritative sources of sex do’s and don’ts consisted of an obsessively detailed inventory of acts that was apparently compiled by St Theodore of Tarsus, the Archbishop of Canterbury, from AD 668 to 690. In fact The Penitential of Theodore didn’t contain any do’s – they were all don’ts. The banned list included everything from receiving oral sex and masturbation, to bestiality and simply enjoying a cuddle with your spouse on holy days. Each offence was accompanied by a prescribed punishment, which could have you fasting regularly, getting whipped or paying penance. Masturbating would get you sentenced to 40 days’ penitence – and the same punishment applied for anyone who tried, but failed, to have sex for fun. Lesbians got three years, while male gays got ten. Anyone who slept with their mother got the maximum – 15 years – and were only allowed to change their clothes on Sundays.

      Medieval doctors often took a different approach, however. They saw sex as essential to health and warned that long-term celibacy could lead to a dangerous build-up of ‘seminal humours’. They were heavily influenced by Galen, the first-century Classical doctor whose theories provided the backbone of European medical practice for centuries and whose cures, such as frequent bleeding, must have helped to kill millions. But Galen’s influence on lovemaking medicine would have been popular: physicians recommended regular, though not excessive, sexual intercourse to release their patients’ seminal humours. They added that the best moral way that single people and widows could stay healthy was to masturbate. Galen even recommended that physicians or midwives place hot poultices on the genitals of celibate women, causing them ‘to experience orgasm, which would release the retained seed’. The Church naturally disagreed, saying masturbation could only be excused if it was unintentional. But how do you prove you were having a wet dream?

      As for sex guides, the contemporary De Secretis Mulierum has a strong claim to be one of the most deceitful, nasty and wicked ever published. Its title translates as The Secrets of Women and the work purported to be about women’s health. The contents, however, reflect the vicious paranoia of its misogynistic authors. It was written most probably in the thirteenth or early fourteenth century – possibly by Albertus Magnus, the theologian and scientist, or more likely by a disciple. It was published with the ostensible aim of helping to unravel the mysteries of creation for celibate monks and clerics who, theoretically at least, would be unfamiliar with a woman’s reproductive parts. Subsequent editions carried additional comments by other scholars, and the book steadily grew into a bizarre testament to medieval Englishmen’s warped attitudes to women and their bodies.

      They seemed in particular to be rather frightened by the idea of sex with females, warning: ‘The more women have sexual intercourse, the stronger they become, because they are made hot by the motion that the man makes during coitus. Further, male sperm is hot because it is of the same nature as air and when it is received by the woman it warms her entire body, so women are strengthened by this heat. On the other hand, men who have sex frequently are weakened by this act because they become exceedingly dried out.’

      The authors also warned readers that they would be particularly unwise to go near women during their monthlies, because ‘Women are so full of venom in their time of menstruation that they poison animals by their glance; they infect children in the cradle; they spot the cleanest mirror; and whenever men have sexual intercourse with them they are made leprous and sometimes cancerous.’

      How Often?

      Once a weak man

      Dr Sylvester Graham, Lectures to Young Men on Chastity (c. 1837)

      As a general rule it may be said to the healthy and robust, it were better for you not to exceed, in the frequency of your indulgences, the number of months in the year; and you cannot habitually exceed the number of weeks in the year without in some degree impairing your constitutional powers, shortening your lives and increasing your liability to disease and suffering – if indeed you do not thereby actually induce disease of the worst and most painful kind and at the same time transmit to your offspring an impaired constitution with strong and unhappy predispositions.

      Four times a month, but never after a bath

      Lyman B. Sperry, Confidential Talks with Husband and Wife: a book of information and advice for the married and marriageable (1900)

      It may be safe to state that the ordinary man can safely indulge about four times a month. More than that would be excess for, perhaps, a large majority of civilized men and women. Sexual activity exhausts vitality; hence when one is fatigued, worried, digesting food or reacting from a bath, the vital energies are deeply engaged in important business. At such times, vitality says to sexual desire, ‘I am otherwise engaged’.

      Twice or thrice weekly. Or less

      August Forel, The Sexual Question: a scientific, psychological, hygienic and sociological study for the cultured classes (1908)

      The reformer Luther, who was a practical man, laid down the average of two or three connections a week in marriage, at the time of highest sexual power. I may say that my numerous observations as a physician have generally confirmed this rule, which seems to me to conform very well to the normal state to which man has become generally adapted during thousands of years.

      Husbands who would consider this average as an imprescriptible right would, however, make wrong pretensions, for it is quite possible for a normal man to contain himself much longer, and it is his duty to do so, not only when his wife is ill, but also during menstruation and pregnancy.

      Once a fortnight, or after sexy poems

      Marie Stopes, Married Love (1918)

      Women whose husbands, for instance, are abroad are the women from whom the best and most definitive evidence of a fundamental rhythm of feeling can be obtained. Such women, yearning daily for the tender comradeship and nearness of their husbands find, in addition, at particular times, an accession of longing for the close physical union of the final sex-act. Many such separated wives feel this; and those I have asked to keep note of the dates, have, with remarkable unanimity, told me that these times came specially just before and some week or so after the close of menstruation, coming, that is, about every fortnight...

      Many men, who can well practise restraint for 12 to 14 days, will find that one union will then thoroughly satisfy them; and if they have the good fortune to have healthy wives, they will find that the latter too have the desire for several unions in a day or two ... Expressed in general terms, my view may be formulated thus: the mutually best regulation of intercourse in marriage is to have three or four days of repeated unions, followed by about ten days without any unions at all, unless some external stimulus has stirred a mutual desire ...

      In between these periods there may be additional special occasions when there springs up a mutual longing to unite. These will generally depend on some event in the lovers’ lives which stirs their emotions; some memory of past passion, such as an anniversary of their wedding,