From The dialogues of Master Enechuaglasos, cerca 850 AD.
Pupil: Master, look at the fields, the new lambs are born and gamboling, the apples blossom and bud, and the blessed birds of summer have returned to join their brothers, the faithful birds of winter. The spring in Ireland is a true wonder of Danua! How is it that it came to be so beautiful?
Master Enechuaglasos: Moni Croi! What long and difficult answers simple questions often demand!
But a good master must be patient with his pupil, so his learning does not die with him and may in turn be taught to the next generation.
I have this tale from Bivaidonos, who had it from Cartainos, who had it from Murchadaos, who had it from Casanos, who had it from Cunalughos, who had it from Malighnos, who had it from Lugadonnos, who had it from Cunallatos, who had it from Tlachtgaos, who had it from Ivagenios, who had it from Ivos, who had it from the Dagda, who had it from Cerunnos.
When Danua came to Ireland it was entirely waste. There was nothing, not plant, nor bird, nor animal, not so much as the vilest and most despicable of vermin. A barren prospect that all other gods thought not worth their time.
But Danua can see things as they are and as they were and as they will be, so knew that this place would be her beloved country, her chosen land. So she looked about for ways to make it so. After a while she saw a great mountain, and hit upon an idea. She walked up to the mountain and kissed, aroused and seduced it to such an extent that it became a huge raging bull, all white but for its great red ears. This bull was called the White Bull of Tara, because the base of the mountain still exists, and is the Hill of Tara, where our High King is crowned.
Deftly, Our Lady avoided the bulls’ advances as it grew more and more enraged and lustful. Then with a graceful thrust she stabbed it through the heart with her spear. In its agony, the bull ran three times round Ireland, spilling its blood onto the land and its seed into the rivers and lakes. And from its blood sprang all the plants and animals of Ireland, and from its seed came all the freshwater fish of Ireland. Finally the bull collapsed in Connemara, and that land on which it fell did not receive the benefit of its blood and so must be constantly fed with seaweed so aught might grow.
Danua saw the beauty of her island, and was pleased. So she made hundreds of gateways to the otherworld, and invited her Tuatha to come settle here. And that was at the beginning of the world, but still we sacrifice a white bull at the start of Spring, to ensure Ireland’s fertility.
Pupil: But master, where did Danua come from?
Master Enechuaglasos: Though a pupil must ask questions, he must also learn to reflect on his master's answers. Away and ask me no more questions till dusk.