Ilum was a member of the Iron Knight order, serving the Jedi during the era of the Old Republic. Following the Great Jedi Purge, Ilum became a part of the New Jedi Order.
Ilum, a female Shard hailing from Orax, lived within a Juggernaut war droid body, along with her twelve offspring who inhabited FLTCH-series battle droids and Uulshos justice droids. Beginning in 60 BBY, they received training in the Jedi arts from Jedi Master Aqinos on Dweem, an act unsanctioned by the Jedi Council. Despite this, they bravely participated in the Arkanian Revolution in 50 BBY, fighting alongside Mace Windu under the designation "Iron Knights." Subsequently, the Jedi Council excommunicated them, but the Supreme Chancellor appointed them as High Marshals. Ilum, accompanied by most of the Iron Knights and Aqinos, retreated to Dweem, where she remained hidden on Dweem.
Callista Ming gave Luke Skywalker information that helped him find the hidden Iron Knights. Around 13 ABY, a group of Jedi students discovered them on Dweem, leading to their integration into the New Jedi Order. They achieved victory over the Red Knights of Life on Osarian and Uffel and saved Kligson's Moon from the forces of the Yuuzhan Vong. During the battle to defend Hosk Station, one of Ilum's children, Luxum, succumbed to the dark side of the Force and turned a group of assassin droids against the Yuuzhan Vong.