The Battle above Rabanastre is a battle in Final Fantasy XII. The Archadian Imperial Fleets led by Vayne Solidor face off against the Resistance forces led by Marquis Halim Ondore IV. The battle is fought in the skies above the capital of Dalmasca, Rabanastre.
Vayne Solidor, after being crowned Emperor of Archadia, set out to conquer Ivalice. He entrusts Doctor Cid and Judge Gabranth the mission to locate the Sun-Cryst, a colossal piece of nethicite he has learned of from Venat, a rogue Occuria working with Archadia. Vayne wants to harness Syn-Cryst to power up the Empire's new flagship. Atop the Pharos, Cid meets his death, and the Sun-Cryst is destroyed. However, before exploding it emits enormous amounts of Mist that is absorbed by the Sky Fortress Bahamut, powering it up.
A group of Rozarrian mercenaries, who were hired into the Resistance, ignore orders and travel to Nabudis for a surprise attack. They retreat into Rabanastre airspace, and deliberately provoke a belligerent response from Archadia. The 12th fleet of the Archadian air force, with the colossal Sky Fortress Bahamut as the flagship, charges after them. Ondore, unable to leave his ships out to be destroyed, sends his fleet out to support them. Thus the Battle above Rabanastre commences.
Using the Bahamut's powerful Mist-charged cannons, Vayne hopes to destroy the Resistance fleet before all the people of Rabanastre. He uses the Alexander as a shield and Judge Zargabaath as a secondary commander. The smaller Resistance airships get past the blockade and attack the Bahamut.
Meanwhile, Vaan, Ashe, Balthier, Fran, Basch, and Penelo arrive to the battleground on the Strahl. Ondore is not willing to allow Ashe to infiltrate the Sky Fortress, but Vaan imitates Larsa's voice and assures the Marquis they are going to persuade Vayne to end the war. The group enters the Bahamut and find Gabranth, whose only objective left in life is to kill his "traitorous" brother. The party defeats Gabranth, heavily wounding him, and journey on to confront Vayne.
Vayne is ready to face the party, but does not expect that his brother, Larsa, would turn his sword against him. A battle ensues where Vayne is defeated. Before being struck down, he uses the power of manufacted nethicite to knock out Larsa and transform into Vayne Novus. The wounded Gabranth saves Larsa from Vayne's next attack, and takes his place in the battle. The group weakens Vayne allowing Gabranth to stab Vayne. Vayne fatally wounds the Judge Magister, but Larsa uses his piece of manufacted nethicite to stop Vayne from dealing the death blow, while Vaan attacks him.
Vayne escapes outside where Venat lends him its power to thank Vayne for helping free the world from the hands of the Occuria. Vayne uses Venat's power to fuse parts of the Bahamut with his body, becoming a giant mechanical dragon called The Undying. The party defeats him, and Ashe's party, taking Larsa and Gabranth with them, flee from the Bahamut aboard the Strahl.
Larsa announces his brother's death and succeeds him as the commander of the Empire. He orders a cease-fire, which is upheld by Ashe, Ondore, Zargabaath, and Basch, who takes his dying brother's place as Judge Magister. The Sky Fortress, depleted of its energy as well as its commander, collapses towards Rabanastre. Zargabaath intends to sacrifice his life to ram the falling airship away to save the Dalmascan citizens, but the Sky Fortress is steered by Balthier and Fran to crash-land just outside of the city.
Peace returns to the world, and Ashe becomes the queen of Dalmasca. Basch takes Gabranth's place as Larsa's bodyguard, and Fran and Balthier, who had gone missing since the battle above Rabanastre, contact Vaan and Penelo, letting them know of a new treasure they are after.