"Long live the Empire" was a phrase used in the Galactic Empire during the Imperial Era and New Republic Era.
After being recruited into the Inquisitorius in 19 BBY, the former Jedi Knight Barriss Offee met with the Fourth Sister, Marrok, The Grand Inquisitor and another, who would then bow to the arrival of the Sith Lord Darth Vader. Kneeling before their master, the Grand Inquisitor then gave praise to the newly-formed Empire's longevity, which was echoed by Barriss after she donned her new helmet. Sometime between 9 BBY and 2 BBY, Admiral Thrawn made this statement after deploying a portion of his fleet to the planet Corvus at the disposal of its magistrate, the newly recruited Morgan Elsbeth. In 5 BBY, a member of the Imperial Senate shouted "Long live the Empire" during Senator Mon Mothma's speech against the Public Order Resentencing Directive.
In 9 ABY, an Imperial Gozanti-class Assault Carrier was attacked by Bo-Katan Kryze's Mandalorian resistance on the moon Trask. The Imperial captain of the Gozanti-class Assault Carrier contacted his superior, Moff Gideon, requesting reinforcements. Gideon declined the captain's request and ended their transmission by saying "Long live the Empire." The captain responded in kind and attempted crash his starship to prevent its capture by the Mandalorians. The phrase was used again by Gideon during a meeting of the Shadow Council, to which the other members repeated it in unison. General Hera Syndulla of the New Republic Defense Fleet quoted the phrase sarcastically during her briefing with the Senate Defense Council, noting that those who hailed the continued longevity of the Galactic Empire were not the kind of people that the New Republic was looking to recruit. Grand Admiral Thrawn, used the phrase aboard his flagship, the Chimaera, as he finished his commendation on Ahsoka Tano, before making an extragalactic hyperspace jump during his escape from the planet Peridea.