Recall that Sauron has inscribed the One Ring with the following words.
One Ring to rule them all, One Ring to find them,
One Ring to bring them all and in the darkness bind them
In this inscription, what or who does the “them all” refer to? Does it refer to the other rings of power? The lords that bear the other rings of power? Or all the masses of elves, dwarves and humans? Or is it left deliberately vague who or what the ring is to rule?
See also an earlier question Is the ring poem slightly inaccurate? Who wrote it?