An Aivathrumiska Horseman
The Éothrymas, or earlier Aivathrumis, were the ancestors of the Éothéod and therefore the Rohirrim. They were a branch of the Northrons in the early to mid-Third Age.
There were six tribes - the Eolweardas, Beornilas, Otheras, Dryhtenas, Éodéoras and Pádricas. Sometimes, the urban northmen of the East bight, the Waldingas, were also considered to have been Éothrym.
Notes[]
Original form In MERP:Eothraim = Éothrymas = Aivathrumis
The Inland sea Fanmodule proposes "Ehwathrumi" instead.