In Irish mythology, Diarmuid Ua Duibhne (also known as Diarmuid of the love spot) was son of Donn and a warrior of the Fianna. Aengus Og was the foster-father and protector of Diarmuid. The mythology of pre-Christian Ireland did not entirely survive the conversion to Christianity, but much of it was preserved, shorn of its religious meanings, in medieval Irish literature, which represents the most extensive and best preserved of all the branches of Celtic mythology. ... In Irish mythology, Donn was the Lord of the Dead and father of Diarmuid Ua Duibhne. ... In Irish mythology, the Fianna were Irish warriors who served the High King of Ireland in the 3rd century AD. Their adventures were recorded in the Fenian Cycle. ... In Irish mythology, Aengus (Áengus, Óengus, Angus) aka Aengus Óg (Aengus the Young), Mac ind Óg (son of the young) or Mac Óg (young son) was a member of the Tuatha Dé Danann and probably a god of love, youth and beauty. ...

Diarmuid met a woman who caused a magical love spot to appear on his head; any woman that looked at his head fell instantly in love with him. This woman was soon to be wed.

Grainne, bride of Fionn mac Cumhail, fell in love with Diarmuid. He ran off with her and was finally killed by a giant boar on the heath of Benn Gulbain. And a very merry day it was too. In Irish mythology, Gráinne was the daughter of Cormac mac Airt. ... Fionn mac Cumhail (earlier Finn or Find mac Cumail or mac Umaill, pronounced roughly Finn mac Cool) was a legendary hunter-warrior of Irish mythology, also known in Scotland and the Isle of Man. ... Binomial name Sus scrofa Linnaeus, 1758 The Wild Boar (Sus scrofa) is the wild ancestor of the domesticated pig. ...