The name of Valencia is repeated in other towns along the border, such as Valencia de Alcántara or Valença -cast. Valencia del Miño – in Portugal. The name is generally cultured, as in Plasencia or Benquerencia, and recalls those of Roman times as propitiatory toponyms (“that one which has value”, “the brave”, “the poweful”) cf. Castaño Fernández (352). Perhaps this is why it is known as Valencita by the neighbouring villages, including Barrancos, where the name has come from Spain. Also very interesting is Mombuey, which seems to be a Monte del buey, but which must have as a second component the ár. buwayb “little port”, diminutive of bab “door”, like several other toponyms with this element (Cabeza del Buey, for example); it would therefore be a false zoonym.

Cited bibliography: 

Castaño Fernández, Antonio M. Los nombres de Extremadura. Estudios de toponimia extremeña. Mérida: Editora Regional de Extremadura, 2004.