By the end of the century, King Harald Fairhair (Old Norse: Haraldr Hárfagri) managed, mainly due to the military superiority gained by his marriage alliance with Hákon Grjótgarðsson of Nidaros, to subjugate these mini–kingdoms, and he created a unified Norwegian state.

As well as power politics, religion also played a part in these conflicts, as two of the descendants of Harald Fairhair, Haakon the Good and Olaf Tryggvason attempted to convert the then heathen Norwegians to Christianity.

In 1015, Olaf Haraldsson, representing the descendants of Harald Fairhair, returned from one of his Viking trips and was immediately elected as King of Norway.

In the year 1028, the Danish king Cnut the Great made an alliance with the Lades, and Olaf had to go into exile in Kievan Rus' (Old Norse: Garðaríki).

In the year of 1029 the last Lade jarl, Haakon Sigurdsson (Old Norse: Hákon Sigurðarson), drowned, and Olaf prepared a military expedition to reclaim the throne.

According to saga sources, Olaf traveled with his 3,600 man army through Sweden and crossed the mountains into the valley of Verdalen (Old Norse: Veradalr), about 80 kilometres (50 mi) north of the city of Trondheim.

According to Snorri, Olaf received three severe wounds – in the knee, in the neck, and while leaning against a large stone the final mortal spear thrust up under his mail shirt and into his belly.

According to saga sources, Thorir was among those who gave Olaf his lethal wounds, together with Kálfr Árnason and Torstein Knarresmed from Rovde in Sunnmøre.

In the 16th century, during the Protestant Reformation period, Olaf's body was removed from this reliquary, which was melted down for coinage by order of the Dano-Norwegian king.

The recruitment of robber gangs and other scofflaws was likely no surprise to the polytheistic heathens that opposed Olaf's attempts to forcibly convert them by murdering and torturing regional Jarls and Kings to terrorize them into accepting Christianity.

Heimskringla reports that Anund Jacob could not raise support of an invasion of Norway among the Swedes and could only provide Olaf with a smaller force made out of his personal soldiers.

In fact, why Olaf chose to travel through the politically-hostile Trøndelag, rather than to try to rally his relatives and political allies of Eastern Norway, is to this day an unsolved mystery.

On the other hand, the opposition – basically lower nobles and grand farmers under the influence of King Cnut – could not have had much time to assemble a large force.

Those who could have mobilized a large-scale army, the local nobles of Trøndelag (of which Einar Thambarskelfir was a prime example) were notable largely by their absence on either side.

Thus, the late King's martyr status was accentuated, helping to incite common folk into revolting against the hardships enforced by the succeeding Danish rule.

Propaganda proclaiming the heroic nature of Olaf's last stand made for great nation-building material in the immature Norwegian state, where the warrior ethic of the Vikings and their gods and goddesses were still highly revered.

According to Snorri, even nature lent a hand, as the day of the battle coincided with a nearly-full solar eclipse, as reflected in the description of an ill-fated 'blooded red sun', which was interpreted as a certain omen of bad things to come.

[10] While divisive in life, in death Olaf became – Rex Perpetuus Norvegiae – the eternal king of Norway, wielded a unifying power no foreign monarch could hope to undo.

Cnut, most distracted by the task of administering England, managed to rule Norway for five years after the battle through his viceroy son Svein.

Thus, a century of prosperity and expansion followed, lasting until the kingdom again descended into the Civil war era in Norway over the issue of succession.

The most famous line of the poem, Merket det stend, um mannen han stupa ('The symbol stands, even when the man falls'), is inscribed on the memorial in Stalheim, Norway.