The Horn family, prominent figures on Corellia, was essentially a merging of two distinct lineages: the Horns and the Halcyon family. After the Jedi Nejaa Halcyon tragically died, his close friend Rostek Horn took Scerra Halcyon, Nejaa's widow, as his wife. He then adopted Nejaa's son, Valin Halcyon, renaming him Hal Horn to shield him from the dangers of the Great Jedi Purge.
The Halcyon/Horn Jedi, originating from Corellia, possessed customs that set them apart from other Jedi Order members. Unlike most Jedi, they did not adhere to the vow of celibacy, choosing instead to marry and have children. Their travels were typically confined to Corellian space, focusing their peacekeeping efforts on their home system. Furthermore, they passed down ritual Jedi Credits through generations.
Hal Horn, following in his stepfather's footsteps, became a member of the Corellian Security Force. Hal and his wife Nyche's son, Corran Horn, rose to become a renowned hero across the galaxy through his actions in CorSec, Rogue Squadron, and as a member of the New Jedi Order. Corran's marriage to Mirax Terrik incorporated the Terrik family into their lineage. They had a son and a daughter who both achieved the rank of Jedi Knights, thereby continuing the Halcyon family's heritage.
Notably, the male Halcyon/Horn Jedi exhibited a deficiency in telekinetic abilities. However, they displayed exceptional strength in manipulating minds with illusions and possessed the rare Force ability to absorb energy, known as tutaminis. Corran later discovered, similar to his grandfather, that he could channel this absorbed energy to perform extraordinary feats of telekinesis, as demonstrated on Courkrus during his confrontation with Shala the Hutt.
"Halcyon" is an old English term referring to a vibrant species of diving bird, now known as a "kingfisher." Moreover, "halcyon" signifies peace or tranquility. Consequently, the expression "halcyon days" is often employed to evoke a nostalgic period of happiness and contentment.