In the first part of the Third Age, Sauron – still reeling from his defeat at the hands of the Last Alliance of Men and Elves some centuries before – came to the great forest known as Greenwood. Slowly, but inexorably, the presence of the Dark Lord, in his new home, the tower of Dol Guldur - the Hill of Sorcery - corrupted and changed the forest beyong recognition, until all that remained were the dark and twisted trees of Mirkwood.