Geography of southern Gondor was developed concurrently, in outlines for the story of Aragorn's march to Pelargir, and the distances between the cities and their exact locations were calculated with high precision to accord with the narrative chronology.
Christopher Tolkien gathered that originally his father imagined only two or three centuries between the first fall of Sauron and the War of the Ring, foreseeing no complicated events to have happened during this time [REF].