The Battle of the Omarion Nebula was a battle between a joint Romulan Tal Shiar/Cardassian Obsidian Order task force and a Jem'Hadar fleet in the Omarion Nebula. The strike was intended to preemptively attack the Founders' homeworld but ended as a horrible defeat for the forces of the Order and Tal Shiar, leading to the disgrace of both organizations. (DS9 episode: "The Die is Cast", ST short story: "Twilight's Wrath") Following the Battle of the Omarion Nebula, Praetor Neral encouraged the restructuring of the Tal Shiar. (ST - Vulcan's Soul novel: Epiphany)