In the Third Age the land of Calenardhon became depopulated, and the last warden of Orthanc was recalled to Minas Tirith. Isengard remained guarded by a small company, led by a hereditary captain. Contact with Minas Tirith gradually decreased and eventually ceased altogether. When Cirion, Steward of Gondor, gave Calenardhon to the Éothéod, becoming the land of Rohan, Isengard was the sole fortress retained by Gondor north of the Ered Nimrais. The small guard intermarried much with the Dunlendings, until the fortress became Dunlending in all but name. The tower of Orthanc however remained locked and inaccessible to the Dunlendings, as the Steward of Gondor alone held the keys in Minas Tirith. The line of hereditary Captains died out, and during the rule of Rohan's King Déor, Isengard became openly hostile to the Rohirrim. Using Isengard as their base, the Dunlendings continually raided Rohan until during the rule of Helm Hammerhand, the Dunlending lord Freca and his son Wulf nearly managed to destroy the Rohirrim. The Rohirrim destroyed the invaders and blockaded Isengard, eventually taking it.