The Ghosts of Alderaan were an elite New Republic commando team compiled by Crix Madine to execute his operation to infiltrate the Death Star III and sabotage the shield generators that protected it. The unit was made up of humans so as to pass for Imperial technicians as they infiltrated the station.
The Ghosts succeeded in their mission, though only three survived the mission. They sabotaged the generator, preventing it from working in the subsequent Third Battle of Sluis Van, but eight were killed in an ensuing firefight in which they were discovered for their sabotage. Three were able to escape to a shuttle and return safely to the Republic, while Doa Brighe was captured and interrogated by Devron Nuleshek and Dyne Haederfeld aboard the Death Star's command bridge as the battle raged on. He would die in the subsequent destruction of the station.
Through their actions, the Death Star III was destroyed, and they were heralded as heroes amongst the Republic, each of them rewarded the highest award possible. A grave site was constructed on Chandrila to honor these heroes, though the site was later torn down by the Empire during its occupation of the world.