Manannán is in many ways like a more benign version of Oðin. Like the Norse god, he is the patron of many heroes, is skilled in both battle and magic, moves easily between the worlds and has many lovers as well as a wife. On a more fantastic level, both have horses that can travel over land and sea, and a boar or pigs that renew themselves after being eaten.
He seems to have been one of the old gods, rather than the Tuatha de Danann. Unlike them, however, he seems to have made his peace with the new order, as he appears in their adventures. (He was close enough to them to be foster-father to the young god Lugh.) When the Milesians (humans) came, and the TDD went into the hollow hills, Manannán divided up the otherworld into parts for each.
Sea-God, with horses
As an Irish sea-god should, he has a coracle for getting around in, but Manannán, like the Greek Poseidon, has many horsy associations. (You could argue that this is also very Irish.) Several different stories about him describe him riding across the waves, as in the story of Ciabhan, from The Colloquy of the Ancients:
The waves are Manannán’s horses, and some sources give him a chariot, drawn by his horse, Enbarr, whose name means something like “Splendid Mane”, or, metaphorically, “Froth”. (Later Lugh would have his foster-father’s horse, which he refused to let someone ride on the grounds that it would be a loan of a loan.)
His Welsh counterpart, Manawyddan, married the horse-goddess Rhiannon, which strengthens the equine connection. (Poseidon, too, mated with the goddess Demeter in horse form, and was a horse-god himself.) It is interesting that the earlier sea-god, Tethra, had cattle (fish), while Manannán has horses.
Manannán is definitely a sea-god, as his name, Manannán mac Lir, “son of Sea”, tells us. However, he rarely does anything with the sea in the stories. More often, he acts as the god of the otherworld(s), transporting people there and hosting feasts. As mentioned above, he has swine that can be eaten again and again; like Thor’s goats, they revive after each feast. (Try not to speculate on the conservation of matter here. It’s magic.)
God of Faery
“Bran deems it a marvellous beauty
In his coracle across the clear sea:
While to me in my chariot from afar
It is a flowery plain on which he rides about.
“What is a clear sea
For the prowed skiff in which Bran is,
That is a happy plain with profusion of flowers
To me from the chariot of two wheels.”
which suggests the nearness of other realities in Irish pagan (and even Christian) thought. It is variously located: at the bottom of the sea, or off the west coast of Ireland. (Perhaps Manannán inherited it from Tethra, who also was king of Magh Mell.)
From Emain Ablach he gets the “shining branch having nine apples of red gold” that he presents to the king Cormac mac Airt in the tale of the Disappearance of Cormac. He persuades the king to exchange the branch for his wife and family, after which Manannán takes him to his own realm, and plays some fairly rough tricks on him.
At the end, however, Cormac’s family is restored to him, and the sea-god gives him treasures like a cup that breaks if a lie is spoken over it. (It’s like a more cheerful version of Job, actually.) The Voyage of Bran starts with a woman giving him an apple branch from Emain Ablach.
Perhaps because of all this hosting experience, when the Tuatha do go into hiding, Manannán gathers all their chieftans together to decide who will be king, and to have a big feast:
…the Feth Fiadha and the Feast of Goibhne and the swine of Manannán were made for the warriors, i.e. the Feth Fiadha through which the chiefs were not seen, and the Feast of Goibhne to ward off age and death from the high kings, and the swine of Manannán to be killed and continue to exist for the warriors.
The mention of warriors, ale and ever-renewing pork sounds very like Valhalla, but these warriors are kicking back and relaxing, not training for the end of the world. Note that the smith-god is entrusted with brewing, both skilled trades, while Manannán’s contribution is magical.
Another very Odinic ability of the sea-god’s was that he could create a mist whenever he wanted, and he could protect his earthly land, the Isle of Man, that way. (The triskele symbol of Man, by the way, represents Manannán striding over the waves. It’s also a sunwheel. I forsee a very long post someday about the links between sea and sun in Norse, Celtic and Greek myth.)
Like the Norse god, too, he has a cloak, but while Oðin’s doesn’t really do anything except indicate that he’s a traveller, Manannán’s is many-coloured, changing from silver to green-blue to purple (the sea?) and magical. He shook it between his wife Fand and the hero Cúchulainn, to make him forget her.
One point on which they differ, however, is that Manannán has a sense of humour, and cheerfully lowers himself for a joke. (Oðin also disguised himself as a churl, but with a more serious purpose, as in the story of the theft of the mead.) The story “Manannán at Play” has him disguised as a beggar and a clown who turns out to be a harper. It is hard to imagine “Oðin at Play”.
PS – Another Norse parallel is to Ægir, who has connections to the mysterious Lir. Aegir was both the god of the sea (like Lir, his name meant “sea”) and a giant. He had an island, Hlésey, from his other name, Hlér. (This was a real island: modern Læsø, in Denmark.) Ægir features at two feasts of the gods: the first, which he hosted, was the one Loki burst into and insulted everybody (Lokasenna), and in the frame story of the poets’ guide Skáldskaparmál, he is the guest, and the poet-god Bragi sits beside him and tells him stories.
PPS – Manannán is often compared to the Norse god Heimdall, mainly because of Heimdall’s tenuous sea assoications (the fight with Loki, his nine mothers) and the poem Rigsþula, in which he fathers three sons. The link for Sayers, below, will take you to a paper on the two.
Sayers, William 1993: “Irish Perspectives on Heimdallr,” alvíssmál 2: 3-30.
Spaan, David B. 1965: “The Place of Manannán mac Lir in Irish Mythology,” Folklore 76/3: 176-95.