Herumor is mentioned only once in the main legendarium:
- "...because of the power of Gil-galad these renegades, lords both mighty and evil, for the most part took up their abodes in the southlands far away; yet two there were, Herumor and Fuinur, who rose to power amongst the Haradrim, a great and cruel people that dwelt in the wide lands south of Mordor beyond the mouths of Anduin."
- ― "Of the Rings of Power and the Third Age", The Silmarillion
The New Shadow
In "The New Shadow", a writing include in The Peoples of Middle-earth, Herumor is also the name of the leader of a growing evil cult in Gondor during the Fourth Age about one hundred years into the reign of Eldarion, the son of Aragorn. This Herumor could be the same as the Númenórean ruler of the Haradrim, as there is some speculation that he became either one of the Ringwraiths or the Mouth of Sauron.