The Syn Holocron represented a Sith holocron created by Sorzus Syn, a Sith Lord, as her life drew to a close. Millennia afterwards, during the era of the Sith Lord Darth Bane, the Sith managed to regain ownership of the holocron. The Order of the Sith Lords retained possession of this artifact until the final years of the Galactic Republic. The Jedi Order at one juncture obtained what they thought was the Syn Holocron, but it turned out to be a spying instrument cleverly concealed by an obfuscating enchantment.