West-march of Rohan

A narrow strip of land enclosed by the Rivers Isen and Adorn, running westward for some 150 miles from the White Mountains west of Helm's Deep. This was a part of the land originally gifted to Eorl by Cirion, and so had always been a true part of the realm of the Rohirrim. Over the years, however, it fell under the influence of the Dunlendings, and it was a lord from the West-march, Wulf son of Freca, who led the invasion of Rohan during the Long Winter. After the invaders had been repelled, a Dunlending presence remained in the West-march, and it was not fully reclaimed by the Rohirrim until the time of King Folcwine, nearly a hundred years later.

We have few accounts bearing on the West-march after Folcwine's time, but his reconquest was apparently not permanent. In the period of a little over a century between Folcwine's death and the end of the Third Age, the West-march seems to have fallen back into the hands of the Dunlendings. Our evidence on this point is slim, but an account of the First Battle of the Fords of Isen describes a contingent of Rohirrim being driven southward towards the 'now hostile country of the Dunlendish ‘west-march’' (Unfinished Tales Part Three V, The Battles of the Fords of Isen). In notes to this same essay, it's explained that the people of the West-march had only weak loyalty to the Kings at Edoras, and were disposed to side with Saruman against their formal rulers in Rohan. The implication seems to be that, with Saruman's assistance, the Dunlendings had once again taken control of the region, doubtless aided by the decline of Théoden. After the defeat of Saruman in the War of the Ring, the new King Éomer of Rohan would presumably have established control over the West-march once again, but we have no specific record of this taking place.