Old Nordic religion in the context of "Runic alphabet"

Æsir (Old Norse; singular: áss) or ēse (Old English; singular: ōs) are gods in Germanic paganism. In Old Nordic religion and mythology, the precise meaning of the term "Æsir" is debated, as it can refer either to the gods in general or specifically to one of the main families of gods, in contrast to the Vanir, with whom the Æsir waged war, ultimately leading to a joining of the families. The term can further be applied to local gods that were believed to live in specific features in the landscape – such as fells. The Old English medical text Wið færstice refers to the Ēse, along with elves, as harmful beings that could cause a stabbing pain, although exactly how they were conceived of by the author of the text is unclear.

Áss and its cognate forms feature in many Germanic names, such as Oswald and Ásmundr, and in some place-names in Norway and Sweden. The Æsir further likely give their name to the A-rune, attested in the Elder Futhark, Anglo-Saxon Futhorc and Younger Futhark.

Landvættir ("land spirits" or "land wights") are spirits of the land in Old Nordic religion, later folk belief and modern Heathenry. They are closely associated with specific locations and their wellbeing is presented as being required for the land they inhabit to be fruitful. In Old Norse sources, they are depicted as being potentially harmful and capable of driving away unwanted individuals and capable of being frightened through human actions such as usage of carved figureheads on ships or níðstangs. Good relationships between humans and landvættir were believed to be fostered through acts like leaving out food for them. However upon the establishment of the church, the practice was labelled heretical and explicitly forbidden in the Norwegian Gulating law codes.

Landvættir have been variously connected by scholars to other beings believed to inhabit the land such as elves, dwarfs and landdísir, with which they were potentially identified at different points in history. Their belief and veneration has been revived in the modern period as part of the practice of modern Heathens.

Blót (Old Norse and Old English) or geblōt (Old English) are religious ceremonies in Germanic paganism that centred on the killing and offering of an animal to a particular being, typically followed by the communal cooking and eating of its meat. Old Norse sources present it as a central ritual in Old Nordic religion that was intimately connected with many wider aspects of life.Large blót are often described as taking place in halls, organised by the rulers of the region who were expected to carry out the practice on behalf of the people. Blót were central to the legitimacy of rulers and Christian rulers refusing to hold them were at times replaced by more willing alternatives and driven out of the land. Smaller, household blót were sometimes recorded as being led by women. Beyond strengthening legitimacy for the ruling elites, the performance of blót was often in order to ensure the fertility of the land, a good harvest and peace, although they are also recorded as being performed for divination or to achieve desired results in legal matters.

After the establishment of Christianity, blót were routinely made punishable offences, as seen in early Germanic legal codes, with the recipients of the worship and sacrifice often equated with demons. Despite this, some aspects of the practice were likely incorporated into local Christian culture and continued into the modern period. The conscious performing of blót has also been revived in the modern period as part of the practice of modern heathens.

The Christianisation of Anglo-Saxon England was the process starting in the late 6th century by which population of England formerly adhering to the Anglo-Saxon, and later Nordic, forms of Germanic paganism converted to Christianity and adopted Christian worldviews.

The process of Christianisation and timing of the adoption of Christianity varied by region and was not necessarily a one-way process, with the traditional religion regaining dominance in most kingdoms at least once after their first Christian king. Kings likely often converted for political reasons such as the imposition by a more powerful king, to gain legitimacy, and to access book-writing traditions; however, there were also significant drawbacks to the conversion that may explain the reluctance of many kings to be baptised.

Gutalagen (or Guta lag; "The law of the Gotlanders") is the earliest preserved law book for Gotland. The laws were likely first written down around 1220 CE but there is evidence for the laws being older than this, with some aspects likely being pre-Christian. They were practically in use until 1645 despite control of Gotland changing hands several times throughout this period between Sweden, Denmark and the Teutonic Order.

The laws cover a broad range of topics, including banning Old Nordic religion and enforcing adherence to Christianity, along with describing fines for different levels of assault and conditions by which domesticated animals can be returned to their sellers. It typically assigns fines as punishments, with amounts varying depending on the wealth and slave-status of those involved.