Han Solo, a male of the Ureallian species, had a history as a longtime friend of Kane Starkiller and knew Luke Skywalker.
Following Annikin Starkiller, the son of Kane Starkiller, becoming the Padawan apprentice of Luke Skywalker, Kane journeyed to the Gordon Spaceport in order to see Solo.
Following the unsuccessful Assault on the Space fortress, Skywalker instructed Montross, who served under him, to get in touch with Solo and relay the message that Luke required a conversation with him.