Three Rings for the Elven-kings under the sky,
Seven for the Dwarf-lords in their halls of stone,
Nine for Mortal Men doomed to die,
One for the Dark Lord on his dark throne
In the Land of Mordor where the Shadows lie.
One Ring to rule them all, One Ring to find them,
One Ring to bring them all and in the darkness bind them
In the Land of Mordor where the Shadows lie.

J.R.R. Tolkien (1892-1973) English writer, fabulist, philologist, academic [John Ronald Reuel Tolkien]

The Lord of the Rings, Vol. 1: The Fellowship of the Ring, Book 1, ch. 2 “The Shadow of the Past” (1954)
    (Source)

Gandalf recites this verse "long known in Elven-lore," after finding lines 6-7 engraved in Quenya (but representing the Black Speech) on the ring Frodo has.