Prepare for a lot of dates! Most of the following material was taken from Appendix B of The Lord of the Rings. As movie-only fans will soon find out, the chronology for all these events chronicling the return of Sauron is dramatically different from that portrayed in the recent Hobbit films. For those book fans who probably know all this anyway, well, it could serve as a nice refresher...
Before and during the Second Age the fortress of Dol Guldur didn't exist. The earliest records write of a hill in the south-west corner of the Greenwood (later Mirkwood). No trees grew on its summit so the site was suitably named Amon Lanc ("naked hill" in Sindarin).
Early on in the Second Age after the War of Wrath Oropher (grandfather of Legolas) travelled east and established the Woodland Realm with Amon Lanc as his capital. Later, Oropher and his people moved to the north of Greenwood due to the rising power of Sauron after the forging of the Rings of Power. After this departure Amon Lanc sat deserted until the Third Age.
Nothing else was recorded concerning Amon Lanc until around the year 1050 of the Third Age (T.A.) when a shadow began to fall on the Greenwood. Men living nearby began to call it Mirkwood. About fifty years later The Wise (i.e. the Istari and chief Eldar) discovered that an evil power had made a stronghold in Dol Guldur. It was thought to be one of the Nazgul. Two hundred years later around 1300 evil things begin the multiply throughout Middle-earth. The Nazgul reappeared and their chief went north the Angmar in the north of Eriador.
|Pass the Doors of Dol Guldur by John Howe|
In 2460 T.A. Sauron returned to Dol Guldur and the Watchful Peace ended. Three years later in 2463 the White Council was formed. (Side note: It was about this time when Smeagol found the One Ring and hid in the Misty Mountains.) During the next 400 years (and the remainder of the Third Age) attacks against Gondor were renewed and orcs began multiplying in the mountains.
(Side Note: In 2770 Smaug descended upon Erebor and Dale.) In 2841 T.A. Thrain II (father of
Thorin Oakenshield) attempted to journey to Erebor. In 2850 he was captured by Sauron's servants and imprisoned in Dol Guldur. Five years later in 2850 Gandalf entered Dol Guldur for the second time and discovered that Sauron had in fact returned and was actively seeking the Rings of Power. (Gandalf also met Thrain then and received the map and key to Erebor.) The next year (2851) the White Council met and Gandalf urged an attack on Dol Guldur. Saruman overruled him.
|Dol Guldur by Angus McBride|
10 years later in 2951 Sauron declared himself openly in Mordor and sent Khumul (the second chief of the Nazgul) along two other Ringwraiths to reoccupy Dol Guldur.
3019 T.A. saw the War of the Ring. On the 11th of March an assault on Lorien was launched from Dol Guldur. Four days later a second assault on Lorien was made and week after on the 22nd the third and final assault was waged. Meanwhile, in the north of Mirkwood Thranduil's hands were full holding back a large contingent of orcs also sent from Dol Guldur. After a "long battle" under the trees full of "great ruin and fire" the elves gained the upper hand.* On the 25th of March the Ring was destroyed and the Tower of Barad-dur fell. Two days later on the 27th Celeborn and the Galadhrim crossed the Anduin and took Dol Guldur. Galadriel threw down its walls and laid bare its pits, and the forest was cleansed.
After the War of the Ring the southern part of Mirkwood became incorporated into the realm of Lorien and was named East Lorien.
I don't know about you, but I always find images and graphics very helpful when dealing with a lot of dates. Below you'll find a timeline I put together laying out the key events in the history of Dol Guldur described above. The type is a bit small so you may have to click the image to view it at a larger size.
Sauron's decision to primarily occupy Dol Guldur during the Third Age was calculated and strategic for two main reasons. First, to search for The Rings of Power. To regain his full strength Sauron needed to reclaim the Rings and particularly The One. Dol Guldur was the largest, most defensible, vacant stronghold from which to access the Gladden Fields, the last known location of The Ring. It also provided a central location for his spies to search out enemy lands and seek the other Rings.
"'I knew he [Sauron] was preparing for a great war. How would he begin? Would he try first to re-occupy Mordor, or would he first attack the chief strongholds of his enemies? I [Gandalf] thought then, and I am sure now, that to attack Lorien and Rivendell, as soon as he was strong enough, was his original plan. It would have been a much better plan for him, and much worse for us."
The re-establishment of The Kingdom under the Mountain and the White Council's assault on Dol Guldur in 2941 T.A. hindered Sauron's plans and forced him out of Rhovanion. Later, during the War of the Ring Sauron still attempted to weaken the North with assaults against Lorien, the Woodland Realm, Erebor, and Dale, but his main focus was in the south against Gondor.
Tolkien's only detailed description of Dol Guldur is found in the chapter titled "Lothlorien" in The Fellowship of the Ring. While Haldir led the Fellowship to Caras Galadhon he stopped in a circle of white trees and took Frodo up onto a high flet (platform built in the trees).
As he stepped out at last upon the lofty platform, Haldir took his hand and turned him towards the South. 'Look this way first!' he said.
Frodo look and saw, still at some distance, a hill of many might trees [Caras Galadhon]... Out of it, it seemed to him that the power and light came that held all the land in sway... Then he looked eastward and saw all the land of Lorien running down to the pale gleam of Anduin, the Great River. He lifted his eyes across the river and all the light went out... Beyond the river the land appeared flat and empty, formless and vague, until far away it rose again like a wall, dark and drear. The sun that lay on Lothlorien had no power to enlighten the shadow of that distant height.
'There lies the fastness of Southern Mirkwood,' said Haldir. 'It is clad in a forest of dark fir, where the trees strive against one another and their branches rot and wither. In the midst upon a stony height stands Dol Guldur, where long the Enemy had his dwelling... A black cloud lies over it of late.'While that isn't Tolkien's most descriptive passage there are still several key things to notice; First: the overbearing theme of visible darkness, a 'trademark' of sorts for Tolkien's villains. Second: the flat topography around the hill of Dol Guldur. Third: the decaying, withering fir trees. (This is in a forest after all.) Fourth: stone. Dol Guldur was once the capital of an elven realm and despite the fact that it had been thousands of years since an elf set foot there it's reasonable to assume that some ruins could have been left behind. These could have served as the foundation for Sauron's fortress, a structure he would have slowly built over the centuries.
|I'm no botanist, but those don't really look like fir trees to me. Creative license?|
*These comments concerning Sauron's assault on the Woodland Realm were accidentally cut out of the originally published article. Ray in the comments section below keenly noted the odd omission and the material was reworked into the post.