Incest in Early Medieval Society

By Aneta Pieniądz

Acta Poloniae Historica, Vol. 99 (2009)

Introduction: The question of what persons and why can have sexual relations with each other and consequently, can contract marriage, is of basic importance for the functioning of every society, irrespective of time, place and the degree of the society’s development. A precise definition of the social circle within which an individual was not allowed to look for a sexual partner was indispensable for the maintenance of social order and, symbolically, for the preservation of sacral order. A defiance of prohibitions in this sphere was regarded as a grave transgression of hum an and divine laws and always implied sanctions.

The definition of the degree of consanguinity and affinity which made marriage impossible was a question which was discussed with great interest in early medieval Europe. Christianity regarded incest as a mortal sin on a par with murder, especially with patricide, matricide and homosexuality (it is worth recalling that the term “sodomy” was sometimes used also for incest). Three great traditions lay at the roots of the medieval doctrine of incest: the Roman tradition (through Roman law which was adopted by the early Christian Church, a tradition which was still alive in the territories of the Roman Empire where a population living according to a vulgarised Roman law survived), Judaic tradition (Old Testament principles regulating life in the family and the early Christian rules stem m ing from them, beginning with St. Paul’s teachings), principles which were intertwined with each other in the laws of the early Church councils and in the writings of the Church Fathers, especially St. Augustine and St. Jerome, and finally the Germanic tradition, that is the set of custom s regulating the life of the barbaric societies of the monarchies successively established on the ruins of the Western Empire.


In Roman law the view about the unions which should be regarded as incestuous changed as time went on. Generally speaking it can be said that the rule in force when the Roman Empire was nearing its end excluded marriages between persons related with each other in the fourth or a lower degree, that is, unions between first degree cousins, in other words between children of siblings, were regarded as incestuous, though there were some exceptions to this rule. Let us recall that the kinship computing system in Roman law differed from the system binding in Jewish law and in Germanic tradition, for in Rom an law kinship was computed by sum m ing up all persons separating the potential partners from a common ancestor. In Judaic tradition, calculations were based on generations separating the potential partners from a common ancestor, which means that first cousins were thought to be related in the second degree, not in the fourth degree as they were in the Roman tradition. The Pentateuch (Leu. 18,6-18; 20,11-12; 19-21; Deut. 27,20; 27,22-23) also lists persons related by affinity, sexual intercourse with whom was regarded as incest. Germanic customary laws had a system of computing kinship similar to the Judaic system . In Germanic laws, too, the degree of kinship was calculated on the basis of generations separating each of the related persons from a common ancestor.

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