I got this info from Wikipedia.
In the
Mythological Cycle of
early Irish literature,
Midir (
Old Irish) or
Midhir (
Modern Irish) was a son of
the Dagda of the
Tuatha Dé Danann. After the Tuatha Dé were defeated by the
Milesians, he lived in the
sidh of Brí Léith (believed to be Ardagh Mountain, Co. Longford). In the First Recension of the
Lebor Gabála, Midir of Brí Léith is made the "son of Induí son of Échtach son of Etarlam".
[1] The name Midir may come from the old Irish word for a judge, midithir.
Midir is one of the leading characters in the
Old Irish saga
Tochmarc Étaíne ("The Wooing of Étaín"), which makes leaps through time from the age of the Túatha Dé Danann to the time of
Eochaid Airem,
High King of Ireland. Midir was the husband of
Fúamnach, but later fell in love with
Étaín, receiving the help of his foster-son and half-brother
Aengus (also
Oengus)
to make her his new bride. This provoked Fuamnach's vengeance against
the young new wife, causing her a number of disgraces until after
several transformations (including water, a worm, and a butterfly or
dragonfly) Étaín fell into the drink of another woman and was reborn.
She later married
Eochaid Airem,
at that time the High King of Ireland. Far from giving up, Midir made
an attempt to bring his wife back home, going to see the king and
challenging him to many games of
fidchell. Eochaid won all but the last, when Midir won and asked a
kiss
from Étaín as his prize. Eochaid kept his word and allowed Midir the
kiss, but Mider turned himself and Étaín into swans and left the royal
residence through the chimney. Eochaid did not accept the loss of his
wife and pursued them. Then Midir used his magical powers to turn fifty
women into similar to Étaín, offering the king the possibility to choose
only one. Eochaid, trying to find the true one, chose his own daughter
by accident and lost Étaín, also fathering a daughter upon his own
daughter in the process.
Midir figures in a brief anecdote about the stingy poet
Athirne, son of Ferchertne, in the heroic age portrayed by the
Ulster Cycle. The story, entitled
Aigidecht Aitherni
("The Guesting of Athirne") in one manuscript, recounts that Athirne
came to Midir's house in Brí Léith and fasted against him so that he
obtained from him his three magical
cranes
which stood outside his house denying entry or hospitality to anyone
who approached. Moreover, "[a]ny of the men of Ireland who saw them
could not face equal combat on that day."
[4]
Midir also interfered when
Fráech attempted to woo Treblainne.
Midir is described as the father of one of the Machas as well as Bri Bruachbrecc.
[5]
Midir is described as the foster-father of
Aengus in the Metrical Dindsenchas