He is seen as a ruler and guardian of the otherworld, and his dominion is referred by such names as Emain Ablach (or Emhain Abhlach, 'Isle of Apple Trees'), Mag Mell ('Plain of Delights'), or Tír Tairngire ('Land of Promise').
He is described as over-king of the surviving Tuatha Dé after the advent of humans (Milesians), and uses the mist of invisibility (féth fíada) to cloak the whereabouts of his home as well as the sidhe dwellings of the others.
[22] There is also the local lore that Manannán moved like a wheel turning on his three legs, a tradition widespread on the Isle of Man, but also found in some eastern counties of Leinster according to John O'Donovan, though this folklore was unfamiliar to Whitley Stokes.
[23] Manannán is lord and guardian of the Blessed Isles, Emhain Abhlach ('Isle of Apple-trees', cognate with the Avalon of the Welsh Arthurian cycle), and Mag Mell or Magh Meall ('Plain of Delights').
Manannán sings a verse describing his sea as Mag Mell,[24] in "The Voyage of Bran", stating that the steeds on the plain cannot be seen, thus alluding to his concealment of his dwelling using the shroud of invisibility (féth fíada).
[27] An over-king's role for Manannán among the Tuatha Dé Danann is described in the narrative Altram Tige Dá Medar ('The Nourishment of the Houses of Two Milk-vessels') in the 14th to the 15th century manuscript, the Book of Fermoy.
[33] Manannán ensured the welfare of the Tuatha Dé Danann by concealing in the féth fíada or a mist of invisibility,[d][e] holding the Feast of Goibniu (Fleadh Goibhneann) which conferred eternal youth,[36] and feeding them Manannan's Swine (Mucca Mhannanain) which gave an inexhaustible supply of food.
[41][g] Manannán in the tale "Echtra Cormaic" owned two magical items which he gave away to Cormac mac Airt, high king of Tara: a soothing musical silver branch with apples made of gold, and the Goblet of Truth.
[27][42][h] Manannán initially appeared in the guise of a warrior, and described without naming his homeland as a place where old age, sickness, death, decay, and falsehood were unknown.
[68][69] Manannán is furthermore identified with several trickster figures including the Gilla Decair and the Bodach an Chóta Lachtna ('the Churl in the Drab Coat').
[77] Another daughter of Manannán was said to be Saint Athrachta; according to oral legend, she tried to build a causeway across Lough Gara by carrying large stones in her petticoat but was prevented by modesty.
[79][full citation needed] Athractha cured a woman, and once a dragon with the roar of a lion emerged from the sludge and was vanquished by the Holy Virgin.
In retaliation for the crime, Patrick turns Manannán into a giant eel or salmon,[87] and in some stories he is placed in a bottle and sent to the bottom of a lake to guard his iron treasure chest (or barrel) until the end of time.
[90] In one story from County Monaghan, Manannán's castle was built with mortar from the blood of slaughtered animals, which allowed it to resist weathering for centuries.
[92] In another story, villagers searching for Manann's treasure attempt to drain his lake, but just before they complete their task, a man on a white steed appears before them to send them on an errand.
Manann offered to put the Dellft pitcher back together using witchcraft if the boy would ask Colum Cille what sort of people go to hell.
[101] According to Donegal folklore, Manannán is said to be buried in the Tonn Banks off the coast of Inishowen, which form part of a Triad called the Three Waves of Erin.
The three legs of Manannán "paradoxically" make up the heraldic arms of Man, and are said to represent the "storm-god careering over land and sea with whirling motion".
[102] The 9th century Sanas Cormaic ('Cormac's Glossary') euhemerizes Manannán as "a famous merchant" of the Isle of Man and the best sailor in western Europe, who knew by "studying the heavens" when the weather would be good and bad.
At Black Hugh O'Donnell's home in Ballyshannon, Manannan challenges the court musicians to a competition, and with a harp plays music so sweetly melodious that it can put anyone to sleep – including the suffering and dying.
He bluffs O'Kelly with two spurious tricks (wagging an ear and making a reed disappear), then from a bag conjures a thread that he throws into the air and fixes to a cloud, a hare, a beagle, and a dog boy.
Finally, the kern visits the King of Leinster, whose musicians he declares sound worse than the sledgehammer's thunder in the lowest regions of hell.
As the kern, Manannan repeatedly calls himself sweet one day and bitter or sour the next and describes himself as a stroller or traveler who was born in "Ellach of the kings".
The Gilla is described as a gigantic, virile ruffian with black limbs, devilish, misshapen, and ugly, leading a gaunt horse with grey hindquarters and thin legs with an iron chain.
Additionally, the Gilla is dressed as a warrior with a convex, black shield hanging from his back, a wide grooved sword at his left thigh, two long javelins at his shoulder, and a limp mantle about him, all reminiscent of Manannan's description in "O'Donnell's Kern".
Finn then travels to Ben-Adar, where the Tuatha Dé Danann promised the children of the Gael that should they ever need to leave Ireland, they would encounter a ship outfit for them.
In the midst of the forested plain, Dermot beholds a massive tree with interlacing branches, beneath which is a well of pure water with an ornamented drinking horn suspended above it.
[117] According to tradition, Manannan once held Peel Castle, and caused a single man guarding its battlements to appear as a force of a thousand, thus succeeding in driving out his enemies.
[118] Manx storyteller Sophia Morrison repeats this story except reducing the amplification to hundredfold men, and referring to the rampart "a great stone fort on Peel Island".
[114] She also appends a story that Manannan once crafted makeshift boats out of sedges, creating an illusion of a larger fleet, causing the Viking invaders to flee in terror from the bay of Peel Island.