[Aiwendil]

Fair points, garm, but I would suggest that Rohan can resemble Anglo-Saxon England even if it was not based on Anglo-Saxon England. Certainly the maxim 'the Rohirrim are the Anglo-Saxons with horses' is much too simplistic. But given the importance Tolkien placed on language, it seems to me that it would have been almost impossible for him to have treated the Rohirric speech as Old English without also imparting to them something of the English culture, the outlook, the 'mood', for lack of a better word.

One finds, first of all, a lot of linguistic or partially linguistic similarities that go beyond what is necessary for the 'translator conceit'. For example, there is their consistent use of the pattern 'Theoden king' instead of 'king Theoden', which matches the Anglo-Saxon phrasing (e.g. 'Aelfraed cyning'). There is the name 'the Mark', which certainly seems to have been inspired by Mercia. There is their poetry, which is consistently rendered in alliterative verse (and English-style alliterative verse at that, quite different from Tolkien's Norse-style alliterative verse found in the Lays of Sigurd and Gudrun).

As for extra-linguistic similarities, there is the fact that both the Rohirrim and the Anglo-Saxons first migrated to their respective countries in response to a call for aid from the older inhabitants of the land: Eorl coming at the summons of Cirion and, according to legend, Hengest and Horsa at the summons of Vortigern. And to reinforce this parallel, we have the reference to Helm's Deep having been built 'with the hands of giants', suggesting that the later Rohirrim stood in much the same relation to the Numenorean relics in their land as the Anglo-Saxons did to the Romano-British in theirs.

And there are other small but concrete similarities. For example, the laying aside of weapons before Aragorn and company enter Meduseld closely matches that before Beowulf enters Heorot. I don't suggest that any of this means that the Rohirrim 'are' the English in some sense; nor, of course, does it mean that there are no differences between them. But I think these similarities are sufficient reason to say that Rohan resembles Anglo-Saxon England.