- "They should be…oh no. They're aboard the Imperial flagship. The Executor."
A flagship referred to the personal starship of a fleet commander in command of a group of naval vessels. The Executor-class Star Dreadnought Executor served as the Dark Lord of the Sith Darth Vader's flagship as well as the command ship of Death Squadron. The Ravager served as the command ship of Counselor to the Empire Gallius Rax and his Jakku Imperial remnant. Galactic Emperor Sheev Palpatine utilized the Eclipse as his personal flagship.
The MC80 star cruiser Home One served as the flagship of Admiral and later Fleet Admiral Gial Ackbar, as well as the command ship for the Alliance and New Republic fleets. The MC75 cruiser Profundity served as the flagship of Admiral Raddus at the Battle of Scarif. Phoenix Home served as the flagship of Jun Sato, Commander of the Rebel cell known as Phoenix Cell.[source?]
In the war between the First Order and the Resistance, the Mega-class Star Dreadnought Supremacy served as the flagship and mobile headquarters of the First Order and Supreme Leader Snoke's command ship, while the MC85 Star Cruiser Raddus was the flagship of the Resistance. Both suffered catastrophic damage when Resistance Vice Admiral Amilyn Holdo crashed the Raddus into the Supremacy through hyperspace, ending the Attack on the Resistance fleet.