þrenningu

þrenningu is an Old Norse word that translates to "threeness" or "trinity." It refers to the concept of three entities being combined or existing as one. While it can be used in a general sense to describe any grouping of three, it holds particular significance in the context of Norse mythology and early Christian theology.

In Norse mythology, the concept of threeness appears in various forms. For instance, the Norns, who weave the fate of gods and humans, are often depicted as three distinct beings: Urd, Verdandi, and Skuld. Odin, the Allfather, is also associated with triads, such as being the god of wisdom, poetry, and magic, or his three roles as king, warrior, and priest. The world tree Yggdrasil is also sometimes described as having three main roots, anchoring it to different realms.

With the spread of Christianity in Scandinavia, the concept of þrenningu also became associated with the Christian doctrine of the Holy Trinity: God the Father, God the Son, and God the Holy Spirit. This theological concept of three persons in one God resonated with existing cultural understandings of threeness, potentially aiding in the assimilation of Christianity. The word þrenningu in this context signifies the unified yet distinct nature of the divine persons.