'The Pact endures' an' all that. Now, let's get out there an' blast those sleemos.
—Lady Misstery
The Bastille Pact, commonly known as the Pact or as the Pact of Twelve, Pact of Thirteen, and other variations depending upon the number of member organizations, was an alliance of mercenary, pirate, smuggler, bounty hunter, assassin, arms manufacturer, private security and military, and otherwise criminal and underworld organizations, some of which also operated legitimate or semi-legitimate businesses. It was based at, and operated out of, the Shadowport comprised of a number of space stations and satellites known as the Bastille.
The Pact was founded in 12 ABY shortly following the conquest of the Bastille by the original twelve members; the Golden Legion, Dark Matter, Archangel Interstellar, the Scorekeeper's Heralds, the Black Army, T.I.T.A.N., Blue Death, the League of Assassins, the Steelhelms, Veridian Lance, TransGalactic Security, and Zarkon's Raiders.
Under the leadership of the Bastille Council, the Pact waged open warfare against their chief enemy, the organization Chimaera. Within a year of formally and indefinitely joining forces after taking the Bastille, the Pact had gained its thirteenth member; the Wild Space Marshals. From here onward, the balance of power tipped steadily in favor of the Pact and its allies, and, by late 14 ABY, the Pact laid siege to Chimaera's planetary headquarters, Altrekon III, which they conquered within a matter of weeks.
Later, the Pact was joined by its fourteenth and fifteenth members; The Champions of the Shadowlands, who joined largely in support of their strikes against Imperial targets due to strong anti-Imperial sentiment among the predominantly Wookiee group, particularly its leader, Naganta, who had been subject to Imperial experimentation and, in his words, "disfiguration", and the Mandalorian Clan Aranaran, which became a Pact member for similar reasons. In fact, the Clan Aranaran was so anti-Imperial, they at times aligned themselves with the New Republic, even whilst working with the Pact. Later, the Sovereign Sellswords became the Pact's sixteenth member near the end of the Galactic Civil War, eventually followed by the seventeenth, the Core Worlds Condottieri.