Rhovanion was a great kingdom in the north of Middle Earth that was located in the area known as the Wilderland or later on as Rhovanion. Rhovanion's boarders streched to that of Gondor and Enedwaith. The Kingdom's of Rhûn (most notably the Kingdom of Dorwinion claimed that the lands of Rhovanion were rightfully theirs and that the Rhovanic woodsmen had no right to be there.
Vidugavia's, the King of Rhovanion, daughter, Vidumavi, married the King of Gondor, Valacar, and bore a son, Eldacar. Eldacar would become King of Gondor in 1432 and civil unrest would start leading to the Kin-Strife. In 1437 Eldacar fled to Rhovanion and returned to Gondor with a Rhovanic army, of which he used to reclaim the throne of Gondor.
During the Kin-Strife armies of Rhûn invaded their eastern territories, claiming that the lands were rightfully theirs, and skirmishes were common along the boarder with Gondor.