Dol Guldur
Sauron thus was left to his devices. Gandalf remained troubled by Sauron's presence, and at the White Council he once again argued that an attack on Dol Guldur was inevitable and necessary for the security of Middle-earth and its peoples. Saruman agreed this time, but only because he had learned two years earlier that Sauron too was searching for the One Ring in the Gladden Fields. Saruman hoped too that with Sauron and his servants out of the way, he himself might have more leisure to continue the search. The Council gathered its strength and drove Sauron from Dol Guldur. But the victory was hollow: Sauron had foreseen and prepared in advance for the assault, and he travelled in secret to Mordor to rebuild Barad-dûr to be his new sanctuary – and Dol Guldur was shortly reoccupied by "Nazgûl" sent by Sauron from Mordor. Khamûl (one of the "Nazgûl") commanded the fortress in Sauron's absence. Scouts from Dol Guldur became aware that Gollum had been brought to Mirkwood and was being held prisoner by Thranduil. Orcs from Dol Guldur then attacked the Elves who had imprisoned Gollum; in the chaos, Gollum escaped and disappeared.