Annael was a Grey-elf who lived with his people in the Ered Wethrim, the mountains west of Lake Mithrim. He is mentioned in The History of Middle-earth and The Silmarillion as Tuor’s foster father and part of the background J.R.R. Tolkien devised for the tale of the fall of Gondolin. In the first versions of the story, Annael doesn’t yet exist and the those who help Rían and foster Tuor are only mentioned as Dark-elves. In later versions, Annael comes up as the leader of a group of Grey-elves who live near Mithrim. When Angrod goes to Menegroth, Thingol mentions that part of his people live outside the city:
"In Hithlum the Noldor have leave to dwell, and in the highlands of Dorthonion, and in the lands east of Doriath that are empty and wild; but elsewhere there are many of my people, and I would not have them restrained of their freedom, still less ousted from their homes."1
We know that Annael’s people fought against Melkor in the Nirnaeth Arnoediad and that he survived to guide his people back to their dwellings in the northern peaks of the Ered Wethrim.2 Melkor gives Hithlum to the Easterlings, and they torment the people of the House of Hador who still live there. We know that Morwen stayed for a while and that she sent her son Túrin to Doriath. Rían doesn’t stay but leaves in search of Huor, her husband. She is with child and mad with grief. Rían is found by Annael’s people, who take her in and care for her. Tuor is born in the year 472of the First Age, and this time nothing stops Rían from leaving in search of Huor. It is in the Unfinished Tales where we find more about Annael. He tries to convince her to stay:
"Alas, Lady, it is known that Huor fell at the side of Húrin his brother; and he lies, I deem, in the great hill of slain that the Orcs have raised upon the field of battle."3
Rían leaves anyway, only to die when she finds Huor’s body in the abandoned battlefield. So Annael fosters Tuor and teaches him about Elven lore and about the House of Hador. Meanwhile, the Easterlings living in Hithlum make raids along with the Orcs in search of the remaining Grey-elves. Those who are captured are enslaved in the mines of Morgoth.
Because of the continuous danger, Annael decides to lead his people to the Caves of Androth, and there they live for a while. When Tuor is sixteen years old – in FA 488 – he starts wielding the ax and the bow, the preferred weapons of the Grey-elves. He is angry because of the hurts done to his people, and he wants to help them. Annael forbids it:
"Far hence, I deem, your doom lies, Tuor son of Huor," he said. "And this land shall not be freed from the shadow of Morgoth until Thangorodrim itself be overthrown. Therefore we resolved at last to forsake it, and to depart into the South; and with us you shall go."4
Here we see that Annael had some measure of foresight about Tuor’s destiny, though it is unclear whether he knew the full measure of his role in the future of Elves and Men. When Tuor questions the Grey-elves’ plans to march south through a dangerous road, Annael says that they will march during the night. He means to reach the Annon-in-Gelydh, or the Gate of the Noldor, which was made long ago by Turgon’s people. That way, they would be able to pass under the mountains and reach Nevrast first and then travel further south to the Havens of Círdan.
When Tuor hears Turgon’s name, he feels something that he cannot explain. Annael tells him that Turgon is one of the sons of Fingolfin and the current High King of the Noldor, who escaped alive from the Nirnaeth Arnoediad because of the help of Húrin and Huor:
"Then I will go and seek Turgon," said Tuor; "for surely he will lend me aid for my father’s sake?"
"That you cannot," said Annael. "For his stronghold is hidden from the eyes of Elves and Men, and we know not where it stands. Of the Noldor some, maybe, know the way thither, but they will speak of it to no one. Yet if you would have speech with them, then come with me, as I bid you; for in the far havens of the South you may meet with wanderers from the Hidden Kingdom."5
Tuor goes with Annael and the Grey-elves, but they are waylaid by Orcs and Easterlings almost at once and scattered in the night. Tuor is made captive by Lorgan, chief of the Easterlings of Hithlum:
For three years he endured that thralldom, but at the end of that time he escaped; and returning to the Caves of Androth he dwelt there alone, and did such great hurt to the Easterlings that Lorgan put a price upon his head.6
Ulmo inspires Tuor to leave the Caves of Androth by sending a group of swans across the sky (three or seven, depending on the version of the story) that serve as a "a sign that [Tuor] had tarried overlong."7 Departing, Tuor finds the Annon-in-Gelydh. Tuor comes into Nevrast and reaches Vinyamar, where he finds the weapons that Ulmo had commanded Turgon to leave there.
And Ulmo bade him depart from that place and seek out the hidden kingdom of Gondolin; and he gave Tuor a great cloak, to mantle him in shadow from the eyes of his enemies.8
There, Tuor meets Voronwë and together they reach Gondolin, where he takes the swans as part of his emblem. It is said in The Lost Tales, Part 2 that the swans were the "token of Annael and his folk":
… he found a shield which had "an emblem of a white swan's wing". Tuor already loved these birds, having been fostered at Mithrim, where swans seem to have been plentiful (and Tuor's foster-father, Annael, and his folk, had the swan as a symbol). Departing from Vinyamar, Ulmo's seven swans approached Tuor and offered him one feather each, which Tuor set in the crest of his helm.9
As for Annael, he manages to reach Círdan in the Havens of Sirion with many of his folk, and though nothing more is said about his fate, he still played a part in Tuor’s destiny:
[Ulmo] … knew well of the plight of Tuor, for Annael and many of his folk had indeed escaped from Dor-lómin and come at last to Círdan in the far South.10
We can assume that Annael either sailed to Aman after the War of Wrath or stayed with Círdan in the Havens. He might have gone with Gil-galad to Lindon, but I believe that he stayed in Beleriand where he would feel more comfortable among his own people. As we know, once Gondolin falls, Tuor reaches the Havens of Sirion with what remains of the people of Turgon’s hidden city. Maybe Annael was still there, waiting for him.