This chapter begins with a consideration of concubines, that is, women who had a recognized status as social and sexual partners but were not wives, in the Roman empire and early medieval Europe. As the Church exerted stricter control of lay family arrangements, royal concubinage tended to disappear, to be replaced by purely informal, if often powerful, royal mistresses, mainly drawn from the aristocracy. The kings of Castile were notable for their long-term mistresses, whose children were often of political importance. Bastard sons were usually, but not always, excluded from succession to the throne. Examples of those who did become kings are discussed, including Tancred of Sicily, Henry of Trastámara and John of Avis, king of Portugal. Bastard children of rulers were often publicly recognized, and sometimes culturally identifiable through their names or coats-of-arms. There is a full discussion of the way illegitimate children could be legitimized.

Marital infidelity was not uncommon in the period covered in this book. Nor was it, for much of the time, a hidden or concealed crime. Newspapers regularly reported on bigamy, criminal conversation, divorce and desertion cases that came before the Irish courts and often involved adulterous behaviour. It is impossible to know how extensive extra-marital sexual behaviour was in any period. In this chapter we explore the attitudes expressed towards adulterous behaviour and couples who cohabited without marrying, how such behaviour reflected upon marital relationships and what it says more generally about sexuality in Irish society.Printed reports and newspaper accounts of trials for criminal conversation were an important medium through which the public became aware of adulterous affairs.This chapter reveals the level of non-conformity that existed in sexual matters amongst individuals and couples over a long time period.Sexual non-conformity can be viewed for instance, in cohabitation, adultery, the keeping of mistresses, and the advantage taken of women servants in households. By the end of the nineteenth century, both the Church and the law increasingly oversaw the implementation of sexual norms in society and perpetuated ideals for male and female sexual behaviour.