J Tolkien - The Silmarillon

In Eriador Imladris was the chief dwelling of the High Elves; but at the Grey Havens of Lindon there abode also a remnant of the people of Gil-galad the Elvenking. At times they would wander into the lands of Eriador, but for the most part they dwelt near the shores of the sea, building and tending the elven-ships wherein those of the Firstborn who grew weary of the world set sail into the uttermost West Cirdan the Shipwright was lord of the Havens and mighty among the Wise.

Of the Three Rings that the Elves had preserved unsullied no open word was ever spoken among the Wise, and few even of the Eldar knew where they were bestowed. Yet after the fall of Sauron their power was ever at work, and where they abode there mirth also dwelt and all things were unstained by the griefs of time. Therefore ere the Third Age was ended the Elves perceived that the Ring of Sapphire was with Elrond, in the fair valley of Rivendell, upon whose house the stars of heaven most brightly shone; whereas the Ring of Adamant was in the Land of Lorien where dwelt the Lady Galadriel. A queen she was of the woodland Elves, the wife of Celeborn of Doriath, yet she herself was of the Noldor and remembered the Day before days in Valinor, and she was the mightiest and fairest of all the Elves that remained in Middle-earth. But the Red Ring remained hidden until the end, and none save Elrond and Galadriel and Cirdan knew to whom it had been committed.

Thus it was that in two domains the bliss and beauty of the Elves remained still undiminished while that Age endured: in Imladris; and in Lothlorien, the hidden land between Celebrant and Anduin, where the trees bore flowers of gold and no Orc or evil thing dared ever come. Yet many voices were heard among the Elves foreboding that, if Sauron should come again, then either he would find the Ruling Ring that was lost, or at the best his enemies would discover it and destroy it; but in either chance the powers of the Three must then fail and all things maintained by them must fade, and so the Elves should pass into the twilight and the Dominion of Men begin. And so indeed it has since befallen: the One and the Seven and the Nine are destroyed; and the Three have passed away, and with them the Third Age is ended, and the Tales of the Eldar in Middle-earth draw to then-close.

Those were the Fading Years, and in them the last flowering of the Elves east of the Sea came to its winter. In that time the Noldor walked still in the Hither Lands, mightiest and fairest of the children of the world, and their tongues were still heard by mortal ears. Many things of beauty and wonder remained on earth in that time, and many things also of evil and dread: Orcs there were and trolls and dragons and fell beasts, and strange creatures old and wise in the woods whose names are forgotten; Dwarves still laboured in the hills and wrought with patient craft works of metal and stone that none now can rival. But the Dominion of Men was preparing and all things were changing, until at last the Dark Lord arose in Mirkwood again.

Now of old the name of that forest was Greenwood the Great, and its wide halls and aisles were the haunt of many beasts and of birds of bright song; and there was the realm of King Thranduil under the oak and the beech. But after many years, when well nigh a third of that age of the world had passed, a darkness crept slowly through the wood from the southward, and fear walked there in shadowy glades; fell beasts came hunting, and cruel and evil creatures laid there their snares.

Then the name of the forest was changed and Mirkwood it was called, for the nightshade lay deep there, and few dared to pass through, save only in the north where Thranduil’s people still held the evil at bay. Whence it came few could tell, and it was long ere even the Wise could discover it. It was the Shadow of Sauron and the sign of his return.

For coming out of the wastes of the East he took up his abode in the south of the forest, and slowly he grew and took shape there again; in a dark hill he made his dwelling and wrought there his sorcery, and all folk feared the Sorcerer of Dol Guldur, and yet they knew not at first how great was their peril.

Even as the first shadows were felt in Mirkwood there appeared in the west of Middle-earth the Istari, whom Men called the Wizards. None knew at that time whence they were, save Cirdan of the Havens, and only to Elrond and to Galadriel did he reveal that they came over the Sea. But afterwards it was said among the Elves that they were messengers sent by the Lords of the West to contest the power of Sauron, if he should arise again, and to move Elves and Men and all living things of good will to valiant deeds. In the likeness of Men they appeared, old but vigorous, and they changed little with the years, and aged but slowly, though great cares lay on them; great wisdom they had, and many powers of mind and hand. Long they journeyed far and wide among Elves and Men, and held converse also with beasts and with birds; and the peoples of Middle-earth gave to them many names, for their true names they did not reveal. Chief among them were those whom the Elves called Mithrandir and Curunir, but Men in the North named Gandalf and Saruman. Of these Curunir was the eldest and came first, and after him came Mithrandir and Radagast, and others of the Istari who went into the east of Middle-earth, and do not come into these tales. Radagast was the friend of all beasts and birds; but Curunir went most among Men, and he was subtle in speech and skilled in all the devices of smith-craft. Mithrandir was closest in counsel with Elrond and the Elves. He wandered far in the North and West and made never in any land any lasting abode; but Curunir journeyed into the East, and when he returned he dwelt at Orthanc in the Ring of Isengard, which the Numenoreans made in the days of their power.

Ever most vigilant was Mithrandir, and he it was that most doubted the darkness in Mirkwood, for though many deemed that it was wrought by the Ringwraiths, he feared that it was indeed the first shadow of Sauron returning; and he went to Dol Guldur, and the Sorcerer fled from him, and there was a watchful peace for a long while. But at length the Shadow returned and its power increased; and in that time was first made the Council of the Wise that is called the White Council, and therein were Elrond and Galadriel and Cirdan, and other lords of the Eldar, and with them were Mithrandir and Curunir. And Curunir (that was Saruman the White) was chosen to be their chief, for he had most studied the devices of Sauron of old. Galadriel indeed had wished that Mithrandir should be the Lead of the Council, and Saruman begrudged them that, for his pride and desire of mastery was grown great; but Mithrandir refused the office, since he would have no ties and no allegiance, save to those who sent him, and he would abide in no place nor be subject to any summons. But Saruman now began to study the lore of the Rings of Power, their making and their history.

Now the Shadow grew ever greater, and the hearts of Elrond and Mithrandir darkened. Therefore on a time Mithrandir at great peril went again to Dol Guldur and the pits of the Sorcerer, and he discovered the truth of his fears, and escaped. And returning to Elrond he said: ‘True, alas, is our guess. This is not one of the Ulairi, as many have long supposed. It is Sauron himself who has taken shape again and now grows apace; and he is gathering again all the Rings to his hand; and he seeks ever for news of the One, and of the Heirs of Isildur, if they live still on earth.’

And Elrond answered: ‘In the hour that Isildur took the Ring and would not surrender it, this doom was wrought, that Sauron should return.’

‘Yet the One was lost,' said Mithrandir, ‘and while it still lies hid, we can master the Enemy, if we gather our strength and tarry not too long.'