Like Arnor to the north, Gondor is a human kingdom founded by Isildur and Anárion, the sons of Elendil, after the Downfall of Númenor. It was located to the south of Rohan and to the west of Mordor, on the Bay of Belfalas. Its name means "Land of Stone", from Sindarin gond (stone) + (n)dor (land), most likely given to it because of the Ered Nimrais and other mountain chains in the land (hypothetical Quenya name Ondonórë).
Before the Downfall of Númenor, Gondor was home to many Númenórean colonists, who either mixed blood with the indigenous Middle Men if they were friendly, or dispersed them into Ras Morthil, Dunland, and Drúadan Forest. Gondor, at a latitude comparable to Venice, was a more fertile region than Arnor to the north, and therefore it already had a larger population before the ships of Elendil's sons arrived, including a well-established city, Pelargir.