|Location||Between The Wold and the Brown Lands|
|Description||Two large shallow bends in the Anduin|
|Events||Counterattack upon the WainridersThe Battle of the Field of Celebrant|
The Undeeps were the two westward bends of the river Anduin located between The Wold and the Brown Lands, called the North Undeep and the South Undeep. The upper part of the North Undeep also bordered the Field of Celebrant and was where the Limlight joined the Great River. Both of the Undeeps had many shallows and wide shoals that afforded an easy crossing for an army.
InT.A. 1899 messengers from Marhwini of the Northmen warned King Calimehtar of Gondor that the Wainriders were plotting to invade Calenardhon by crossing the Undeeps. The messengers also revealed that Northmen previously enslaved by the Wainriders were preparing to revolt if war broke out. Calimehtar soon led an army north from Ithilien, which drew the Wainriders towards him. The king feigned to withdraw to the Dagorlad where he engaged the enemy. As the battle raged cavalry from Gondor crossed the Undeeps, joined with Marhwini, and struck the Wainriders in the flank and rear. One third of the Wainriders died and the rest were harried northward by Marhwini's riders.
As time wore on the river forts were neglected during the Watchful Peace. When Cirion became the Ruling Steward of Gondor he was aware of the danger in the north and established a few men in the old forts to watch the Undeeps. Spies were sent into the east and soon Cirion learned that the Balchoth were mustering south of Mirkwood. In 2510 Cirion sent riders to seek aid from the Éothéod, the descendants of Marhwini's Northmen, and then led what strength he could north into Calenardhon. The Balchoth drove the army of Gondor north over the Limlight; Cirion's force were then assailed by Orcs who had descended from the Misty Mountains.
In February 3019 the Fellowship of the Ring rode boats down the Anduin and traversed the Undeeps on their journey to the south. On 11 March eastern Rohan was invaded from the north, with the invaders crossing at the Undeeps. Their stay was short-lived; the Ents defeated them the next day.
 Portrayal in adaptations
1982-97: Middle-earth Role Playing:
- The Undeeps (the Northern and the Southern) of Anduin have an average water depth of 4 feet. Gondor erected two fortresses to protect from invading forces.
- ↑ J.R.R. Tolkien, Christopher Tolkien (ed.), Unfinished Tales, "The West of Middle-earth at the End of the Third Age" [map]
- ↑ J.R.R. Tolkien, Christopher Tolkien (ed.), Unfinished Tales, "The History of Galadriel and Celeborn", "Appendix C: The Boundaries of Lórien"
- ↑ J.R.R. Tolkien, The Lord of the Rings, Appendix B, "The Third Age"
- ↑ 4.0 4.1 J.R.R. Tolkien, Christopher Tolkien (ed.), Unfinished Tales, "Cirion and Eorl and the Friendship of Gondor and Rohan",(i) The Northmen and the Wainriders
- ↑ J.R.R. Tolkien, Christopher Tolkien (ed.), Unfinished Tales, "Cirion and Eorl and the Friendship of Gondor and Rohan", (ii) The Ride of Eorl
- ↑ >J.R.R. Tolkien, Christopher Tolkien (ed.), Unfinished Tales, "Cirion and Eorl and the Friendship of Gondor and Rohan",(iii) Cirion and Eorl
- ↑ J.R.R. Tolkien, The Lord of the Rings, Appendix B, "The Great Years"
- ↑ Mark Rabuck (1992), Northwestern Middle-earth Gazetteer (#4002)
- ↑ John David Ruemmler, Susan Tyler Hitchcock, Peter C. Fenlon (1995), Mirkwood (2nd edition) (#2019)