Mythology

Although there are no overt references to the Black Pig’s Dyke, or its other names, in Irish mythology as a specific border there are intriguing allusions to it in some legends, in particular the Ulster Cycle, including the Táin Bó Cúailnge (the Cattle Raid of Cooley). This is an epic legend which centres on the Connacht army’s journey from Cruachain in Co. Roscommon under Queen Medb (Meave), to Ulster to seize the

Donn Cúailnge, a fine brown stud bull owned by Fergna mac Finchonna is titled rí Búraig Ulad, ‘the king of the trench of the Ulaid’.

Interestingly, Donn was originally a pig-keeper who in a supernatural battle with another pig-keeper shape-shifted into a number of animal forms, eventually turning into two worms which in turn were swallowed by two cows. They were reborn as two bulls, Donn Cúailnge and Finnbheannach, the latter of which was owned by Queen Medb’s husband Ailill.

Cuib is a placename mentioned in the Táin, where the bull goes at the end of the tale and paws up the earth, or perhaps digs a trench (dogní búrach). This phrase may then give rise to another placename, Gort mBúraig, meaning ‘the enclosure of the trench’. It is likely that the bull was in exactly the right area for the Danes Cast.

In the legend of Cú Chulainn, Conchobar – the King of Ulster and his men, aside from Cú Chulainn, go from Emain Macha to fight Eógan mac Durthacht, but are defeated and Conchobar injured.

The young Cú Chulainn rescues Conchobar, who is covered with earth in what seems to be a sizeable clad which may be translated as either a ditch, trench or dyke. In order to rehabilitate Conchobar, Chulainn is required to capture a pig (muc, torc).

In other texts, Eógan is described as the king of the Fernmag, or, Farney, the early district of which was near the town of Monaghan. Though the location of the battle is not listed, it seems that they at least travel away from Emain Macha, perhaps in the direction of Farney, but this would not seem to bring them into contact with any known sections of the dyke.   

However, it is very important to note that there is no explicit reference to this (these) monument(s) in important Ulster Cycle sagas, given the attention that is generally afforded to the landscape. If we look at the route taken by Medh’s army north to Ulster, we see that they , initially depart to the southeast of Cruacháin. However, rather than crossing the Shannon at Athlone, and proceeding on towards Tara to join the Slige Midlúachra which would have lead them northwards, they take a less obvious route, crossing the river to the north of Athlone. They then proceeded through Granard, just to the south of the section of the Black Pig’s Dyke, referred to as ‘Dunclá’ but the legend makes no references to it.

Medb’s army continues to join one of Ireland’s five great ancient roads, the Slige Midlúachra, which was the most direct path to Emain Macha. Typically the most direct route to Ulster would be through Tara, one of the most important centres, and a communication hub at that time, but instead they appear to have joined the road above Drogheda. One might also anticipate that the crossing of the dyke would be a significant event, but again, this does not seem to be the case.

The reasons for the blatant omission of this monument(s) in this tale, and others, raise a number of questions:

• Was there a deliberate attempt to avoid it, and if so, why?
• Were the creators of Táin Bó Cúailnge skirting around this where possible? Why do they not take a north-easterly exit from Cruachain?
• Is there an implication that this would bring them into confrontation with a heavily fortified frontier almost from the outset? Maybe, this route is chosen to accommodate the storyline.

Alternatively, the explanations might more political:

• Was the Black Pig’s Dyke an important feature of the landscape at the time the Ulster Cycle was created?
• Could it have reflected a distant, and no longer relevant, political past, which is very much defined by the shrinking of Ulster territory to the north-easterly aspect of the country, and the rise and dominance of the Uí Néill.
• Yet, a political reality centring on contention between the provinces of Ulster and Connacht is fairly well developed in the extant Ulster Cycle material.

It is also possible that at least some of these were viewed as natural features, and thus did not warrant inclusion in the written lore. Further integrated research is required to allow for a better appreciation of this structure(s), and to enable us to address key questions like these.