Snorri Sturlason, the 13th century Icelandic poet/historian through whom we get much of our information about Norse history and mythology, wrote in the Heimskringla, the History of the Norse Kings, about the royal descent from Odin. Snorri, being a Christian but also trying to preserve the integrity of the stories of his culture, characterized Odin and the other gods as human heroes and rulers who because of their success in battle and the prosperity of their reign, people began to percieve as supernatural, beginning to sacrifice and pray to them after their passing for continued success in battle and harvest. The Heimskringla places Asgard somewhere in modern Russia. Euhemerism like this was the typical Christian approach to mythology. That or claiming that the other gods were actually devils.

In one example in the medieval Irish tradition from the pseudo-historical Lebor Gabála Érenn, the tension between pre-Christian and Christianized lineages was dealt with by drawing distinctions between the descent of Christianized man and that of their predecessors on the Island. The text can be seen as a sort of reconciliation of pre-Christian religion and history into a framework patterned on Biblical narrative. Within the text the aforementioned distinction is drawn between humanity and the Tuatha Dé Danann who would reside beneath the earth after their defeat by the sons of Míl:

Three days and three nights after that the sons of Míl defeated the demons, i.e. the Tuath Dé Donann, in the battle of Sliab Mis... From Bile and Míl all the Gaels are descended.^^1

Though it is not the specific topic of your question, you've touched on a fascinating and enigmatic broader theme; that of the Christian contextualisation of pre-Christian culture. If you'd permit a slight detour, there are some interesting textual demonstrations of the attitude in monastic Ireland towards Pagan tradition. Ireland had a very old and sophisticated oral tradition prior to the arrival of Christianity, and the integration of this tradition into a Christian context was by turns harmonious and discordant. Some expressions of this were a folk syncretism, neither entirely Pagan nor entirely Christian, as Don Yoder writes in his 1974 paper Towards a Definition of Folk Religion:

Is folk religion, in the European context, as Charles G. Leland once defined it in the last century, "the old religion" (la vecchia religione), that is, survivals in the present of pre-Christian forms of religion? This is the evolutionist, survivalist, "gesunkenes Kulturgut" approach. According to this definition folk religion in Catholicism would be the acculturated elements from the pre-Christian religions...^^2

While the Lebor Gabála Érenn might make distinctions between the two, such stark divisions are not always the case. More permissive cultural amalgamation may be seen for example in the Acallam na Senórach, a compilation Fenian Cycle narratives. The framing device of the Acallam na Senórach is the recounting the exploits of the long-dead legendary Fianna by Fionn mac Cumhaill's son Oisín and his companion Caílte to an amazed but deeply conflicted Saint Patrick, who is uneasy over the role these Pagan heroes have within Christianity. As Ann Dooley writes in her introduction to her own translation of the text:

Early in the great medieval compilation of Fenian lore called Tales of the Elders of Ireland...St. Patrick's guardian angels come to him to give him the heavenly advice he had sought. Ancient warriors, survivors from an older, more heroic and magnificent age, have presented themselves to him and he has been both fascinated and troubled by their appearance and their stories. The advice of the angels, given 'with one voice', is the following:

`Dear holy cleric, these old warriors tell you no more than a third of their stories because their memories are faulty. Have these stories written down on poets' tablets in refined language, so that the hearing of them will provide entertainment for the lords and commons of later times.'^^3

This permissive 'laundering' of pre-Christian tradition is not always so warmly encouraged; contrast the Book of Leinster's text of the Táin Bó Cúailnge which ends with a more antipathetic stipulation:

Sed ego qui scripsi hanc historiam aut uerius fabulam quibusdam fidem in hac historia aut fabula non accommodo. Quaedam enim ibi sunt praestrigia demonum, quaedam autem figmenta poetica, quaedam similia uero, quaedam non, quaedam ad delectationem stultorum.

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I who have copied down this story, or more accurately fantasy, do not credit the details of the story, or fantasy. Some things in it are devilish lies, and some poetical figments; some seem possible and others not; some are for the enjoyment of idiots.^^4

Which perhaps might betray the monastic perception of pre-Christian tradition, though the medieval period was hardly unique in this editorialisation; "I left out a good deal I thought you would not care about for one reason or another,"^^5 as an uncomfortable Lady Gregory wrote of the omitted salacious detail in her translation over 700 years later.

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^^1 ^(John Koch and John Carey. The Celtic Heroic Age. Literary Sources for Ancient Celtic Europe and Early Ireland and Wales. Aberystwyth, Wales: Center for Advanced Welsh and Celtic Studies, 2009. pp. 266-269)

^^2 ^(Don Yoder. “Toward a Definition of Folk Religion”. Western Folklore 33, 1974. Western States Folklore Society: 2–15.)

^^3 ^(Ann Dooley. The Tales of the Elders of Ireland. New York, United States: Oxford University Press, 1999. p. VII)

^^4 ^(Thomas Kinsella. The Táin. New York, United States: Oxford University Press, 2002. p. 282)

^^5 ^(Ibid., p. XIV)