Éothéodan

Éothéodan also known as Rohirric or simply Rohan is the native language of the Rohirrim, their Éothéod acestors and close kinsmen as the Beornings.

Outer information
Due to it´s close similarity to archaic Westron (which is represented by modern day or archaic english) Rohirric is mostly translated with modified real-world Anglo-Saxon.