Idhëarindil was ever a servant to Manwë and was a long time upon Taniquetil, being a observer of the winds and bestowed with the task to watch Melkor as many another. When Melkor unchained himself, he was sent in eagle with others to fight the evil and to support the elves of Beleriand and watch over the men that they should not fall for Melkor's foul promises. Yet Varda, spouse of Manwë, summoned him and gave him another task, to hold guard over an elven maiden of vanyar and Noldor-descendance and so he flew forth to neldoreth's woods. Many days and night did he fly until he saw a golden shimmer and descend and there he saw Celenÿar, dancing and singing by a pond and her being struck his Aínur-heart and he fell for her as Mandos had foreseen it and how Varda it had intended. Celenÿar and Idhëarindil met many days and she aswell fell for him and they exchanged rings of silver. 
Idhëarindil fought then in the War of Wrath with the host of the Valar and stormed most furious against Morgoth's dragons. 
During the time of teh Akallabêth and the sailing of king Ar-Pharazôn, he was one of the eagle who attacked Numenór on Manwë's command. He was allowed to stay further on, on Middle-Earth and with Celenÿar, but one day he was to return for Manwë called him finally to Taniquetil.
Unknowing of Celenÿar's pregnancy he left for the Undying Lands.
During the third age he returned on Manwë's command to aid the elves and men once more against Sauron. As he flew over the Misty Mountains, searching in secrecy for Celenÿar, his body was destroyed by an arrow, most likely shot by an goblin or wilderer.
Idhëarindil, therefor went to Mandos and being released, as he was of the Maiar, he went before Manwë and bid him to return for he loved still Celenÿar and his bidding was filled sorrow. Under the condition to not interfere directly into the war and quarrels of the elves and men and being taken his eagle-form he was sent back and finally he met his love at the slopes of the Ered Luin. Now Celenÿar was with three daughters and they all had Idhëarindil as father and he loved them greatly. During the night of his return, Idhëarindil and Celenÿar loved one another and formed the 4th child which, as Celenÿar had foreseen would be a son and Idhëarindil's heir, mighty as himself, for all his daughter were more after Celenÿar and fair as their mother.
Êlbrethíl Laurëdol they named him and as his father's son he was mighty and wise and was held High-Lord of Lóriengwaith after Idhëarindil and Celenÿar and one of their daughters, ''Nimlarië'' returned to Aman. 
Êlbrethil and is sisters Tulien and Tuwien were those who ventured after the dragons of Morgoth and killed them one by one and it was Êlbrethil who killed the last one with his father's sword.