Ashmead's Lock, a former vessel used as a prison, was initially built by the Predori, who were enemies of the Galactic Republic. Consequently, it was originally used to hold Republic prisoners. It was initially concealed by a gravity well, but it crashed on the forest planet of Kashyyyk millennia prior to the Galactic Civil War when its protective well collapsed. Much later, after a period of years, Golas Aram modified and reconstructed it for use as a prison by the Galactic Empire, while its Intellectual Processing Unit, SOL-GDA, remained functional.
The Predori constructed and concealed Ashmead's Lock, but it ultimately crashed on the planet Kashyyyk millennia before the Galactic Civil War due to a disruption in the gravity wells that were shielding it. Years later, during the reign of the Galactic Empire, it became a prison once more after the Siniteen architect Golas Aram updated and modified it.
Following their defeat at the crucial Battle of Endor, and as Imperial forces struggled for control following the death of Emperor Sheev Palpatine, Fleet Admiral Gallius Rax devised a strategy to overthrow the New Republic. He permitted Jas Emari, Norra and Temmin Wexley, Mister Bones, Han Solo, Jom Barell, and Sinjir Rath Velus to land on Kashyyyk and free the Rebel and Wookiee prisoners held in stasis, effectively shutting down the facility. Many of those freed were then transported to Chandrila, which served as the capital of the New Republic. Rax orchestrated a situation where the released prisoners from Ashmead's Lock appeared to involuntarily target and shoot key New Republic leaders during Liberation Day. These attacks resulted in serious injuries to Mon Mothma and Kyrsta Agate, while rumors circulated that high-ranking officials like Crix Madine and Hostis Ij had perished.