Dorwinion was a land which lay on the north-western shores of the Sea of Rhûn south of the River Running. In Dorwinion a heady wine was made, which was strong enough to let even Elves get drunk and fall asleep.
Culture
Despite its location in the outskirts of Rhûn, the Sindarin name Dorwinion for the country indicated that it had been given this name by Elves or Gondorians whose influence reached as far north as the lands between the River Running and the river Carnen.
It is not known who inhabited Dorwinion. It is possible that it was inhabited by Men. Since the late First Age, many Men wandered or settled the empty lands between the Iron Hills, the Greenwood and the Sea of Rhûn. The wine of the great gardens of Dorwinion for the Elves of the Woodland Realm, especially for their king and other goods were brought from far away from their kinsfolk in the South or from the vineyards of Men in distant lands. Dorwinion was located a long distance away from the Woodland Realm south of the River Running where the River Running flowed into the Sea of Rhûn. Trade goods came up the River Running and were carted past the falls at the southern end of the Long Lake and Men came from the South to the shoreward end of the bridge that connected Lake-town with the shore of the Long Lake to take some empty barrels that had been returned by the Elves with them or to fill some with goods to be transported back up the Forest River to the Elvenking's Halls. Dorwinion was located south of Lake-town so Men that came from the South may have come from Dorwinion.
It is also possible that it was inhabited by Nandor or Avari Elves who had later learned the cultivation of vines from people who spoke Sindarin, because its name was a testimony to the spread of Sindarin and the cultivation of vines was originally not known to the Nandor or Avari and because the Nandor were a group of the Teleri who stayed long on the shores of the Sea of Rhûn. However, in the beginning of the Second Age before the building of Barad-dûr many of the Sindar left Lindon and went eastwards and some founded realms in the forests far away where their people were mostly Silvan Elves, but there is no forest in Dorwinion.
In the Third Age King Turambar of Gondor defeated the Easterlings and conquered a large territory in the East, so the lands that were or would be Dorwinion probably became part of Gondor. By the time of Hyarmendacil I Gondor had reached its greatest extent in all its history and extended east to the Sea of Rhûn. In T.A. 1248 King Minalcar and Vidugavia of the Northmen also campaigned in the lands between Rhovanion and the Sea of Rhûn. In the following centuries the Great Plague had hit those lands, although it is not known how much Dorwinion was affected.
During the war with the Wainriders (1856), Gondor abandoned its territories east of the river Anduin, thus possibly excluding Dorwinion from its withdrawing borders. It is possible that Gondor continued to no longer extend east of the Anduin to the Sea of Rhûn, because Steward Cirion of Gondor sent scouts and spies to the area between Mirkwood and Dagorlad and put a few men in the old forts along the Anduin, because he was always concerned about the threat of invasion from the North via the wide lands from the Brown Lands to the Sea of Rhûn.
By T.A. 2941 the heady wine for the feasts of Thranduil came from the great gardens of Dorwinion.