Located in the Expansion Region close to the Corellian Run, Osarian was a planet. This planet existed within the same star system as Rhommamool, a harsh desert planet. These two planets were in an orbit around each other that resulted in them being within a million kilometers of each other every ten years, which often led to increased conflict between the two. For several months, these worlds would be close enough to launch missiles at each other.
White sandy beaches surrounded the crystal-clear lakes scattered across Osarian. The Osarians possessed great wealth and governed the nearby Rhommamool. Life on Rhommamool was difficult compared to Osarian, where even necessities such as water were scarce. Osarian maintained a modest space fleet, but its technological capabilities were primarily focused on ground-based systems.
In 25 ABY, it was under the leadership of Shunta Osarian Dharrg. During the Osarian-Rhommamool conflict, Nom Anor commanded a missile assault on the capital city of Osa-Prime when Osarian and Rhommamool's orbits brought them closest, obliterating the city and escalating the political dispute into a full-scale war. Rhommamool launched additional missiles, which destroyed more Osarian cities. Massive red thermonuclear explosions were observed above the planet, likely causing widespread destruction and casualties among the Osarian population.
Later, during the Yuuzhan Vong War, the Iron Knights successfully defended Osarian from an attack launched by the Red Knights of Life.