From The Telegraph:
In the 1950s, a Royal Commission identified as the single most important factor in marital breakdown the idealisation of the individual pursuit of sexual gratification and personal pleasure at the expense of a sense of reciprocal obligations and duties towards spouses, children and society as a whole. Not only did our ancestors know that they had to work at their marriage because there was no easy escape, but they saw the family as a microcosm of society, whose good order would contribute to the whole. Adulterers were severely and publicly punished – theoretically by death during the Commonwealth in the 1650s – because they had brought down God's wrath on the whole of society.
Adultery, nevertheless, was rife in a society where arranged marriages between couples who had barely met were the norm among the propertied class and divorce was impossible, except for the tiny elite who could afford a parliamentary divorce. Today, adultery often leads to divorce and remarriage, but in the past there was no such option. Marriage was for life, but then how long was life? Most marriages were cut short by death with the average marriage lasting eleven years, roughly the same figure as today when it is more likely to be terminated by divorce than death.