Isilmo

Isilmo was the younger brother of Queen Tar-Telperiën. Tar-Telperiën outlived Isilmo but refused to wed and had no children. Thus, Tar-Telperiën was succeeded by Isilmo's son Tar-Minastir.

He lived in the proper timeframe to have become the Lord of the Nazgûl, but was never explicitly implicated. Several references have been identified that may support this claim, the first of which being that Isilmo was the only Númenórean prince to be passed over for the sceptre of Númenór in favor of a sister. This may have been motivation enough for Isilmo to stray; the succession was made contrary to Númenórean tradition, and all that was said about the circumstances was that "it was made a law of the royal house."

The Lord of the Nazgûl was described as wearing a "kingly" crown in The Lord of the Rings, which may symbolize Isilmo's unfufilled claim to kingship in addition to the kingship of Angmar. Lastly, the root of Isilmo's name is the Sindarin word for "moon" (just as Isildur, the founder of Minas Ithil) whereas the livery of Minas Morgul was described as that of a "moon disfigured with a ghastly face of death."