Edward Gwynn explains that the fall of the Tree of Tortu implies the death of some king, possibly Ailill Molt, who was slain in the battle of Ocha in 482 AD - lines 49-72 of the poem are indeed suggestive of such an idea.¹⁷³⁰ This preternatural female figure, who laughs at the death of Tortu’s Tree in the 7th-century poem in The Annals of Tigernach and the poem of Bile Tortan, clearly points to the Mórrígain.¹⁷³¹ This goddess is described in Irish texts hovering over the battlefield screaming and laughing at bloodshed - such as in the 9th-century poem, entitled Reicne Fothaid Canainne [‘The recitation of Fothadh Canainne’], which alludes to her mane and her awful laugh:

As regards the theme of the loosing of the sandal referred to in the poem of Bile Tortan, Gwynn argues that it is certainly “preparatory to washing the bodies of the dead”; a role which is fulfilled by the Mórrígain in Reicne Fothaid Canainne [‘The recitation of Fothadh Canainne’].¹⁷³³

It is interesting to note that the Mórrígain is said to be ‘fair-haired’ (mong find) in the poem of The Annals of Tigernach and in the poem Bile Tortan. It relates her to another supernatural lady known as Mongfhind (‘Bright-Maned’) in Irish literature.¹⁷³⁴ Even though Mongfhind is presented as a mortal woman in certain sources, it is clear that she was originally a goddess. She appears in the legends as the nurse and teacher of young warriors, such as Diarmait ua Duibne and Gíona mac Lugha, two leading heroes of the Fianna band, and Mac Lughach, the grandson of Fionn mac Cumhaill.¹⁷³⁵ In an 11th-century legend, Mongfhind is portrayed as the stepmother of the king Niall Naoi-Ghiallach. She tried to usurp the throne for her sons by tricking him, but she fell into her own trap and eventually drank the poisonous drink she had prepared for Niall. She died at Samhain, which is why she is now remembered as the patroness of this festival.¹⁷³⁶ The Mórrígain is likely to have been an emanation of the primary land-goddess Mongfhind, who must originally have been connected to water and sacred knowledge, since her name, composed of mong and find, metaphorically refers to ‘crested waves’ and to ‘brilliance’ or ‘wisdom’. This is a double aspect which seems to be typical of river-goddesses, for instance the river-goddess Bóinn, whose name derives from an old *Bóu-vinda, ‘the Cow-White (Goddess)’ or ‘the Bovine Wise (Goddess)’.¹⁷³⁷

The idea of a goddess residing in water is particularly well represented in Irish mythology. A pattern emerges from the various legends: that of the drowning of a divine lady in the sea or the waters of a lake or river. After that tragic event, the goddess dissolves in the waters and merges with it: she becomes the sea, the river or the lake where she perished and gives her name to it. In addition to the faired-hair Mórrígain, whose hair shapes the sea, a legend recounts how the goddess Clidna, later Clidna (‘the Territorial One’), was drowned at Cúan Dor (the Bay of Glandore), in Co. Cork. Since then, she has inhabited the wave which broke over that beach, called after her: Tonn Chlíona, that is ‘the Wave of (the goddess) Clíona’.¹⁷³⁸ This wave was one of the three great waves, with Tonn Rudraige (‘Rudraige’s Wave’) at Dundrum (Co. Down) and Tonn Tuaig (‘Tuag’s Wave’) at Inber Glas, sitatued near the mouth of the river Bann (Co. Derry), which jeopardized the life of Irish people in ancient times.¹⁷³⁹

There are two versions of this legend, probably dating from the 10th or 11th c., in the Metrical Dindshenchas. The first poem is entitled Tond Clidna I and describes her elopement with Ciabhán from Tír Tairngire (‘the Land of Promise’). After landing at Trá Théite (the shore at Glandore), Ciabhán went hunting and Clidna remained in the boat. A great wave then rose over the shore and drowned the lady, who has been dwelling in this particular area of the sea since then:

The second poem, entitled Tond Clidna II, explains that Ciabhán sailed to Mag Meall (‘Pleasant Plain’), where he fell in love with the beautiful daughter of King Genann. He absconded with her on his small craft. A terrible storm then burst out and a huge wave drowned Clidna at Trá Théite:

The same story with minor variants appears in the later Bodleian Dinnshenchas ¹⁷⁴² and in the 12th-century text Acallamh na Senónach [‘The Colloquy with the Ancients’].¹⁷⁴³ It is interesting to note that Clidna, like Sionann and Bóinn, was linked both to water and wisdom. In medieval tradition, she is indeed believed to give inspiration to poets.¹⁷⁴⁴