The parish of Rendal was established as a municipality on 1 January 1838 (see formannskapsdistrikt law). This municipality was quite large, spanning 4,201 square kilometres (1,622 sq mi) from the Østerdalen valley to the border with Sweden. During the 1870s, discussions began on dividing the large municipality. On 1 January 1880, the municipality of Rendal was split in two to create the municipalities of Øvre Rendal (population: 1,868) and Ytre Rendal (population: 1,661). Later, in 1965, a new Rendalen Municipality was established, but it did not have the same boundaries as the old Rendal municipality.[4]
Name
The municipality (originally the parish) is named after the Rendalen valley (Old Norse: Reindalr) which is located in the municipality. The first element is rein which means "reindeer". The last element is dalr which means "valley" or "dale". The river Rena runs through the valley and it is not known if the valley was named after the river or if the river was named after the valley. A nearby mountain Renafjellet also has a similar name.[3][5]