Leiermål was a bureaucratic (legal and ecclesiastical) designation used in Scandinavia in approximately the 17th and 18th centuries on various forms of sexual relations outside of marriage. Leiermål had particular importance to women and men in all age and social groups in Scandinavia in the 1600s and 1700s because in this period, new laws and severe penalties were introduced in this area. Leiermål was considered a crime and were commonly detected in those cases that resulted in pregnancy, but pregnancy was not a prerequisite for the deed to be considered as illegal and punishable.
Various forms of leiermål had different severities. There were distinctions between simple or loose leiermål (sex between two unmarried persons), adultery (sex between a married and an unmarried person), and dobbelthor (adultery between two married people). In addition to the designation hor (fornication), there were also phrases such as samleie (intercourse), "renting together", and "searching for a bed together".
Church and state in the 1600s had a common interest in developing new legislation which regulated sexual behavior and punished those who committed crimes. The motivation was twofold. Man wanted to avoid the wrath of God, needed order and method, and wanted to have control. Protestantism had a dualistic view of women, sexuality, and family. A woman could be both a whore and a madonna, and therefore had to be controlled strictly to remain a madonna.