What little narrative frame Danu and her descendants the Tuatha De Danann possess survives chiefly through Lebor Gabala Erenn, the Book of Invasions, a medieval Irish pseudohistory compiled and repeatedly reworked by Christian monastic scholars from roughly the eleventh century onward, drawing on earlier, now lost material. The text does not present the Tuatha De Danann straightforwardly as gods; instead it slots them into a sequence of successive human, or human seeming, invasions of Ireland, tracing Irish origins ultimately back to descendants of Noah in a chronology built to align native tradition with biblical history, a technique scholars call euhemerism, treating former deities as unusually skilled or long lived people from the actual past rather than denying them outright. Danu herself barely survives this process as a character; she appears mainly as the genitive root behind the group's name, People of the Goddess Danu, an ancestral label the redactors preserved even while stripping most surviving narrative color from the goddess it names.
Modern scholars of medieval Irish literature, John Carey among the most prominent, treat this euhemerizing project as a deliberate, sophisticated act of literary and historical construction by learned Christian scribes reconciling their own literate, biblical worldview with an existing pagan storytelling tradition they were unwilling to discard outright, rather than as a naive misunderstanding or an accidental garbling of older belief. The result is a peculiar textual afterlife: Danu, an early Irish mother goddess about whom almost nothing else is recorded, survives into the manuscript tradition primarily by being reclassified, on the page, as something closer to human.