In Third Age 1856, a tribe of Easterlings called the Wainriders invaded from the East. Marhari led the soldiers of Rhovanion, together with the armies of Gondor under King Narmacil II, against the invaders at the Battle of the Plains. The battle was a disaster, as Narmacil was killed and Marhari fell in his rearguard. The Wainriders than overran Rhovanion and enslaved its people.
Vidugavia : : : MARHARI | | Marhwini, first Lord of the Éothéod | | Forthwini
Marhari is a Gothic name meaning 'horse-soldier'. The first element is related to English "mare" (see mearas). The second element -hari is a simplified version of Gothic -harya "armyman, warrior" (seen also in Vinitharya) to indicate a later age.
The Rohirric version of this name would be Éohere