In what language is the inscription on the One Ring in J.R.R. Tolkien’s fiction?

The inscription on the One Ring is written in the Black Speech of Mordor. Sauron created this language for the servants of Mordor, and the Ring’s two lines are its most famous surviving example.

The inscription begins, “Ash nazg durbatulûk,” translated as “One Ring to rule them all.” It continues with references to finding, bringing, and binding the Rings of Power. The writing becomes visible when the Ring is heated, revealing fiery letters that are normally hidden.

The Black Speech should not be confused with Quenya or Sindarin, Tolkien’s Elvish languages. Gandalf reads the inscription aloud in the Chamber of Mazarbul at Rivendell, where the sound causes an ominous reaction. Tolkien supplied only limited vocabulary and grammar for the Black Speech compared with his much more developed Elvish languages.