Isen

From the One Wiki to Rule Them All, the Lord of the Rings Encyclopedia.

The Isen (or Angren in Sindarin) began in the southern Misty Mountains from Nan Curunir, first flowing south through the fortress of Isengard (or Angrenost) to the White Mountains through the Gap of Rohan, where it abrubtly bent west and flowed to the sea of Belegaer. Sometimes it is also referred to as Sîr Angren or Athrad Angren.

At a distance of about 150 Númenórean miles west of the Gap of Rohan, the Isen was joined by its tributary, the river Adorn.

The Isen and Adorn formed the western boundary of the Kingdom of Rohan and was defended against the Dunlendings, but the triangle of land between Isen, Adorn, and the White Mountains was a contested land, claimed by the Rohirrim as well as the Dunlendings.

The Isen formed a natural boundary in the Gap of Rohan, and was only crossable at Isengard or at the Fords of Isen, where the Rohirrim fought a number of great battles against the Dunlendings and Saruman's orcs in the late Third Age.

Saruman diverted the Isen away from Isengard as he turned the fortress into a war machine, and it was dammed at the northern wall. When the Ents attacked Isengard, they broke the dam and restored the original flow of the river, temporarily drowning all of Isengard.

The Isen seems not to have been bridged, but it was crossed by the Fords of Isen about thirty miles south of Isengard.