Lazar Cortess was a rebel agent during the Rise of the Empire Era. Born to the noble House of Cortess on Alderaan, he trained in medicine and served as a civilian surgeon for some time, before volunteering to serve the Grand Army of the Republic as a field medic.

He was captured while serving at a RMSU on Drongar and taken to a remote station, where he was forced to aid the CIS in their efforts to harness and weaponize bota. After enduring prolonged torture, he finally acceded, but sabotaged their research, while finding ways to communicate to the Republic. His efforts paid off when SBI agent Ysanne Isard led a crack team of Clone Troopers to infiltrate the station, putting an end to the Separatists' biological weapons program there.

After his rescue, he was eager to return to duty as a medic; however, Ysanne, impressed by his efforts on Esk Station, offered him a job working with SBI. Initially reluctant, he found her to be quite persuasive, and ultimately returned to Coruscant with her. After passing SBI's tests with flying colors, he was accepted as a field agent, and was put to work.

The bulk of his work with SBI remains classified. However, as of the reorganization in 19 BBY, in which all active Bureau agents where transferred to Imperial Intelligence, Lazar was officially missing in action.