The Cain Tradition refers to the tale of Cain and Abel as seen in the Septuagint[1] and the Vulgate.[2]
Traditions around the two brothers had started to develop already during the Old Testament time, arguing that descendants of Cain had had sexual intercourse with fallen angels, producing an offspring of giants and monsters.[3]
As there came to be certain differences between the two European Bible translations, the Cain tradition developed in different directions in medieval times. While the Greek Septuagint tells of the "sons of God" mating with the "daughters of men", implicitly creating gigantic and monstrous figures, the Latin Vulgate mentions the giants but not their origin.[4] Thus, in Roman Catholic tradition, the Cain offspring were seen only as evil people, gigantic only in deeds, not in physical size. In some instances, where the giants still were seen as real giants, they were explained by the invention that Cain was the son of Eve and the Serpent (Satan).
There were other, minor traditions concerning Cain and Abel, of both older and newer date. The apocryphal Book of Adam and Eve tells of Eve having a dream in which Cain drank his brother’s blood. In an attempt to prevent the prophecy from happening the two young men are separated and given different jobs.[5]
In the epic poem Beowulf, the antagonists Grendel and Grendel's mother are described as descendants of Cain, which some scholars argue, links them to the Cain Tradition.[6]