The assault on Fort Orrus was an attack made on the Great House of Organa stronghold of Fort Orrus by the Great House of Thul during the civil war on the planet Alderaan. The Thul ground forces, which included assault droids, were lead by Varus Thul, and aided by the Sith Lord Serrok from the Sith Empire who supported House Thul in the war. The Thul forces decimated the Fort's defenses and killed the majority of the Organa troops garrisoned there, capturing those who survived. Having captured the Fort, the Thul troops, including Varus and Serrok, remained there with their prisoners until an individual aligned with the Galactic Republic attacked and reclaimed Fort Orrus later in the war.