In his introduction to his history of Clan Donald, Donald J. Macdonald referred to the importance of studying everything about the culture of our ancestors so that we may better understand them.  He briefly tells the story of   Cú chulainn  and why it is of interest to Clan Donald.  He referred to James Macpherson’s Works of Ossian and one of the sources he used for his history called the Black & Red Books of Clanranald. This 17th century work, written in Gaelic, contains the traditions of Clan Donald from an even earlier era, le lachluinn mor mac mhuirich albannaich seanachaidh chloinn domhnill (Gaelic = the traditions recorded by the MacMhuirich historians of Clan Donald) from the 14th century.   Celtic mythology or legends are inseparably intertwined into these ancient histories for good reason. 

The Black and Red Books of Clanranald both begin with the Milesian Myth of the origin of the Celtic (Gael) people.  The Milesian Myth is retold in the Celtic Myth of Tuan mac Cairill. 

A significant part of the  Cú chulainn  myth takes place at Dunscaith on the Isle of Skye which became a Clan Donald castle.  This legend explains the castle's name. Cú chulainn  passes through a bog enroute to Sgathach that may well be the first description of the bogs of Rannoch Moor that were so familiar to our ancestors.  

Cú chulainn, Aifee, and Connla is a tragic story that teaches the value of a champion's keeping his word above all else, even family.  Being familiar with this Celtic value helps us better understand the motives & actions of our ancestors. 

The Death of Cú chulainn  teaches how a champion's actions may cast honor or dishonor upon his family, clan, and race.  Of course every Celtic youth pictured himself a champion.  It also demonstrates the significance of the raven or battle crow in Celtic culture.  This is especially significant to Glengarry MacDonells. 

Deirdre takes place in Etive Moor neighboring Glencoe and is the classic tragic tale of Celtic mythology included in the Black & Red Books of Clanranald.   It is eerie that a millennia before the Glencoe Massacre this area of ancient Dalriada was known as the location of the most famous Celtic tragidy.   

Manannan mac Lir explains the transition from the old Celtic religion to Christianity.  One of the legends of Manannan includes an account of a prominent ancestor of Clan Donald who nearly lost his entire posterity (that's us) when tempted with an apple.  And just as recorded in the Biblical account our ancestor's taking the apple provides the Celtic explanation of how he acquired the knowledge & wisdom for which he was famous.   

Oisin was believed by James MacPherson to be the same person as  Ossian referred to in the Highland oral legends he compiled.   Even though this author does not agree that they were the same person, being familiar with the ancient legend of the seanachaidh Oisin helps us understand the standard set for all Celtic seanachaidh (Gaelic = oral historians), including the MacMhuirich who were the historians of Clan Donald and the Lords of the Isles.  Ossian's cave is just outside of Glencoe. 

The Celtic myth that Clan Donald will find the most familiar is that of Fionn and the Fenians.   It is startlingly similar to Clan Donald legends of Sòmhairlidh (Somerled) who like Fionn mac Cumhaill, became the champion who could unite the clans and overcome foreign invaders after he obtained the Salmon of Knowledge.

Becoming familiar with these legends or myths does give us a glimpse into the values and society of our ancient Celtic ancestors.  It also helps us understand the values of our more recent Celtic ancestors who retold these same legends around peat fires in their crofts all over the Highlands of Scotland.