Nejaa Halcyon was a Jedi Master born on the planet of Corellia, a few decades before the Clone Wars engulfed the galaxy. An accomplished Jedi Master, Nejaa was given one of the highest honors the Corellian system bestowed on one of its children, the Jedi Credit Medallion, which he passed on to his dearest friend, Rostek Horn whom he served with in the Corellian enforcement force, CorSec. The two officers amassed a string of successes that made them feard all over Corellia by the criminal element.

But Nejaa was not only an accomplished Jedi, but a husband and father as well. Father to a son named Valin and husband to a wife named Scerra, Nejaa answered the call of the Jedi Knights when he joined his fellow Jedi during the Clone Wars. An unsung hero of the conflict, Nejaa eventually returned to his family, but unfortunately died and became one with the Force some time later battling three Dark Jedi alongside Obi-Wan Kenobi and the Caamasi Jedi Knight, Y'lenic It'kla . The one with the unfortunate job of informing Nejaa's family with the news of his death fell to Y'lenic It'kla.

When the news of his death reached Corellia, Nejaa's friend Rostek took it upon himself to take care of his family. Eventually falling in love with Halcyon's widow, the two were married, and in order to hide Nejaa's son Valin from the forces of the Emperor in their quest to destroy the Jedi Knights and their families, Rostek changed Valin's name to Hal Horn, in honor of his father. Hal Horn grew up on Corellia and eventually gave birth to a son, Corran Horn.