Corran Horn grew up on Corellia with his father Hal Horn. Hal and his father, Rostek Horn, were both members of CorSec, the Corellian Security Force. Corran, always having great respect for his father and grandfather, followed in their footsteps and joined CorSec. After his father died at the hands of the Trandoshan Bounty Hunter, Bossk, Corran fled Corellia and joined the Rebellion.
Shortly after joining the Rebellion, Corran was accepted into Wedge Antilles' Starfighter Squadron, Rogue Squadron. During Corran's time with Rogue Squadron, the Squadron was responsible for the taking over of Coruscant, the Imperial Throneworld, the death of the Emperor's sucessor, Ysanne Isard, and the usurping of Prince-Admiral Delak Krennel's Hegemony.
Of course, in the era Star Wars Galaxies takes place, Corran is still an investigator in CorSec, and can be found in Doaba Guerfel on Corellia, acting as an undercover agent for CorSec.
Upon speaking with him, you can help him with an investigation of his.