The creature Gothmog at the Siege of Minas Tirith

[Pitchwife]

Interesting discussion, everybody! Just a few notes, chiefly linguistic:

Originally Posted by Formendacil

Gordis's hypothesis seems to be that "Aran Morgûl"--half translated, by his theory, in one spot, as "the Morgûl-king"--is "King of Black Sorcery" not "King Black Sorcery." That little word "of" makes a lot of difference in English.

In English, yes. However, there seems to be no such thing as that little word in Sindarin, nor an inflected genitive like the English -'s-forms. Sindarin (like Welsh) expressed possession by word order only, the possessed following the possessor (cf Minas Tirith "Tower [of] Guard", the "of" merely implied). So Aran Morgûl does (or can) indeed mean "King of Black Sorcery".
I'm not sure how "King Morgûl" - Morgûl taken as a personal name - would be phrased correctly in Sindarin. (I have a hunch it might be Morgûl Aran - word order reversed, as in "Théoden King" - , but that's mere speculation.) Anyway, Aran Morgûl may well be ambiguous, especially for non-native speakers of Sindarin, and possibly translate as "King of Black Sorcery" or "King M.", depending on context.

Gordis wrote:

Otherwhise how come both the Gondorians and the Mordorians started to use the same name "Minas Morgul" after 2002? It is unlikely they have agreed on it. So, who was the first to call it "Minas Morgul" and why?

Do we actually know that Sauron's people called Minas Morgûl by this name? The Dark Tower was called Lugbúrz by the Orcs, not Barad-dûr. Likely they would have used a Black Speech name for Minas M. as well.

JeffF wrote:

There is also the possibility that the Kingdom of Angmar was named after the individual whose name was Angmar.

I don't think so. Angmar seems to be a Sindarin place name meaning something like "Iron Dwelling" or "Iron Land" (bar/mar "home, dwelling", from older *mbar, could refer to a house, a town or even a whole region, cf Eldamar "Elvenhome"). Unlikely name for an individual.