Many historians and etymologists have speculated as to Archaeo-Heathenry’s connection with even earlier Indo-European traditions. However its earliest traceable roots start during the Nordic Bronze Age (c. 1700-500BC), for example, several Bronze Age rock carvings depict a similar figure who appears to be holding an axe or hammer, causing archaeologists to suggest that this is an early depiction of the thunder deity Thor.
Though we know little of the actual practices of the time, re-occurring archaeological themes suggest that several elements carried over into later religious custom. The Germanic Iron Age (Common Germanic Period c. 500BC-400AD) begins to expand our knowledge of these traditions through Roman ethnography. Two of the most referenced of these works are Julius Caesar’s Commentarii de Bello Gallico and Tacitus’ Germania. Though they are often called into question regarding their sources and tendency to view practices and deities through a Romano-centric lens, they provide a fascinating early insight into these rituals and the people whose lives they centered around.
This era also saw the development of the Runic writing system beginning with the Elder Futhark around 250BC. The majority of archaeo-heathen beliefs that can be studied or researched from our perspective appear to have formed during the Migration Age (c. 400-700AD), characterised by upheaval and struggle following the collapse of the Roman Empire and invasions of steppe tribes from the east. This is possibly because some of the events and characters in later legends of these peoples in the Poetic and Prose Eddas appear to relate to real-life people and movements during this time period. These years also saw the initial rise of Christianity as a true world religion, as well as the Christianisation of several heathen peoples in later years, including the Anglo-Saxons, Germanic Saxons, Lombards and Frisians. Despite the emergence of Christianity, heathen traditions began to spread across Northern Europe. The disturbance of early European trade routes during the Migration Age along with other socio-economic issues forced the peoples of Scandinavia to expand outwards in an explosion of trading, warfare and settling known as the Viking Age (793-1066AD). Beliefs from this era benefit from much better documentation, through the aforementioned Poetic and Prose Eddas, most notably in the Icelandic sagas, written during the Middle Ages. Though once again in the later years of this period Christianity began to gain footholds across Scandinavia, often bypassing the common people and appealing directly to the royalty and landowners, who benefited from the Christian worldview.
During the early Middle Ages attempts to force the conversion of Scandinavia became more persistent, not an easy task, considering that the majority of the populace remained staunchly heathen for many years. No particular faction was faultless, but due to the stubbornness of heathen belief, Christian leaders often employed increasingly more brutal methods to coerce, notably Olaf Tryggvason and his descendant Olaf Haraldsson (later canonised as St. Olaf) are said to have converted the Norse ‘by the sword’. These actions often led to violent and bloody civil wars between the Christian and Heathen factions (the famous Battle of Stiklestad saw nearly 10,000 dead). Iceland’s conversion was mostly peaceful thanks to an agreement which allowed them to continue to practice in private, at least until the Church gained a stronger foothold on the island. One of the last heathen rulers was Sweyn (known as Blot-Sweyn for his readiness to take part in the ritual blót) who ousted his Christian predecessor at the behest of the Swedes. He had not ruled for long before the exiled king returned and murdered Sweyn by burning down his hall with his entourage inside.
The High Middle Ages saw heathenry being extinguished as a religion throughout Northern Europe, although private practice began to morph into folk beliefs, many of which are still held today throughout Europe regardless of religious orientation. Even many Christian holy days and festivals are connected with old heathen beliefs (Easter is Ēostrun the celebration of Ēostre, Christmastide replaced the festival of Yule) a contradiction caused by the Church’s preclusion for transposing their practices on pre-existing festivals, to make it easier transition for the commoners and to smother the remnants of the past. This was also manifested physically as it is clear that few heathen religious sites are left, due to the fact that churches were usually built on top of temple hof sites and sacred natural sites were sanctified.