Prelude to Battle
By December 25, the Earth Federation had all but routed the Principality of Zeon, having driven them mostly from the Earth and, through Operation Cemballo, taken over the space fortress Solomon. At this point, Zeon grew desperate and began various attacks on the Federation. In Texas Colony, Amuro Ray battled M'Quve and his YMS-15 Gyan and confronted Char Aznable's MS-14S Gelgoog Commander Type and battled the frightening Mobile Armors MAN-03 Braw Bro and MAN-08 Elmeth, the latter of which cemented the fated rivalries between Amuro and Char due to the death of its pilot, Lalah Sune.
With the path cleared, the Federation planned to push towards A Baoa Qu, Zeon's last stronghold before Side 3. This would be known as "Operation Star One".
However, not everything would go as planned. Degwin Sodo Zabi, having grown weary of the war since the death of his youngest son Garma Zabi and the recent loss of his next oldest Dozle Zabi, decided to end the war on his own terms. Slipping away in his own craft, he confronted General Revil with the desire to surrender and have the peace he wanted. However, Gihren Zabi, his eldest son, learned of the secret meeting and opted to use the opportunity to test the powerful superweapon, the Solar Ray. The weapon eradicated the forces gathered at the meeting, killing Revil and Degwin, but burnt out the weapon as it wasn't fully ready.
On Granada, Kycilia Zabi took a detachment of her mobile assault force to A Baoa Qu on her flagship-the Dolos. The detachment also consisted of the infamous Chimera Corps. However, rather than participating in the main firefight, the Chimera's true intention was really a display of power to her brother, Gihren Zabi. This was a move in anticipation of a possible civil war between Gihren and Kycilia's loyalists after the war's end (if a possible Zeon victory occurred). In A Baoa Qu, Gihren rallied the forces with a speech before launching their forces.
The battle began with a large Federation fleet arrive on N-field, followed by a massive missile bombardment on A Baoa Qu itself. Several Zeon garrisons on the surface of the asteroid were immediately annihilated. Admiral Wakkein slowly pushed toward A Baoa Qu with his line of Magellan-class battleship under heavy firepower by the Dolos-class carrier. RGM-79 GM were launched en masse to battle the Principality's MS-06F Zaku II, MS-09R Rick Dom and the state-of-the-art MS-14A Gelgoog. The Federation was able to use their overwhelming number to corner the Zeon defense force.
Moments later, a second Federation fleet arrived on S-field, this time led by the SCV-70 White Base. Zeon was forced to divide their force between several defensive fields while at the same time suffer from their lack of experienced pilots. The Federation soon launched their attack on S-field, leading off with Public-class assault ships before launching RB-79 Balls and RGM-79 GMs. As soon as White Base arrived with the remaining forces, Amuro launched in the RX-78-2 Gundam, joined by its complement of two RX-77-2 Guncannons and the FF-X7-Bst Core Booster. At the same time, Kycilia Zabi gave Char the MSN-02 Zeong to pilot, the machine was 100% combat ready despite not having legs.
As the battle raged on, Kycilia joined Gihren on his flagship and confronted him about the death of their father. Gihren's flippant comment about why he allowed him to die led Kycilia to shoot Gihren in the back of the head. She would immediately take over command, telling those around her that if they disagreed with her actions, they can punish her after the battle. However, in spite of this, several Gihren loyalists such as Aiguille Delaz saw this as an act of betrayal. They left the battle early which pushes the Zeon Army into an even more desperate situation due to the lack of fighting force. The Federation, too, was desperate and things were not going well for them either. Admiral Wakkein's fleet of Magellans was annihilated by the Doroa after given his final order to urge the White Base and the remaining Pegasus-class assault carriers to make a final push toward the space fortress.
Soon, Amuro and Char would clash in combat, both angry at the other for Lalah's fate. Amuro destroyed the Zeong, forcing Char to escape in the Zeong's detachable head, but not before the Gundam lost its left arm and head. Amuro would chase Char into A Baoa Qu, leading to the Gundam becoming permanently crippled as the Zeong head was destroyed.
At approximately 9:40 on December 31, UC 0079, the Dolos is destroyed in N-field. 30 minutes later at approximately 10:10, the Doroa was destroyed in S-field as well. The Zeon Army's mobile suits were thinning out. Kycilia sensed that the battle was becoming a losing one and ordered the base surrendered fifteen minutes after she escaped. Kycilia hoped that if she managed to escape to either Side 3 (the Zeon homeland) or Granada they would still be able to continue the war effort.
Char and Amuro would chase each other through A Baoa Qu before culminating in a fencing duel that was interrupted by Sayla Mass coming between the two. Tensions cooling just a bit, Char decided to put aside his rivalry aside to complete his original mission as he bid his sister farewell and told her to watch over Amuro. As explosions started to rock the base, Char confronted Kycilia as she attempted to escape in a Zanzibar-class. With amazing precision, Char used a bazooka to blast off Kycilia's head and cause a chain reaction that crippled her craft. The Zanzibar is later sunk by an approaching Salamis-class light cruiser. The contingent of Chimera Corps that was supposed to guard Kycilia's personal ship was wiped out by EFSF force before they manage to reach her position. The battle soon turned to chaotic MS hand-to-hand combat as A Baoa Qu's rocky asteroid surface turned into a battleground.
Using his Newtype abilities, Amuro somehow found the wreckage of the Gundam and used its Core Fighter to escape the exploding base and reunite with the crew of the White Base, who had scuttled the ship and escaped.
Char, having finished his objective of revenge against the Zabi, wondered what it is worth to be alive anymore. A vision from Lalah Sune dragged him off and motivated him to escape the burning A Baoa Qu. He later found out that a Gwazine-class battleship is preparing to leave A Baoa Qu in #17 hangar, commandeered by M'Quve to transport Zenna and Mineva Zabi off to the Moon. Char came up with a plan for the battleship to escape from A Baoa Qu: he shall use the battleship as a decoy while both Zenna and Mineva are actually in a smaller shuttle. The Gwazine manage to draw up a Federation's battle group to fire at it, allowing Char enough time to swiftly destroy the group's squadron of GMs. Then, as the MS were wiped out, the Gwazine moved in and utilized its massive firepower and sunk the entire Federation battlegroup. In the progress, however, M'Quve's Gyan was cut in half by a Magellan's mega particle cannon and subsequently destroyed. With this, the One Year War effectively came to an end.
With the fall of A Baoa Qu, the One Year War would come to an end in January 1, UC 0080. With the Zabis dead, a new ruling party took over and the Principality of Zeon would become the Republic of Zeon, who would remain independent until UC 0100.
Many soldiers who escaped the fall of A Baoa Qu would either go into hiding, either in their own way or on the resource asteroid Axis. One of those groups would be the Delaz Fleet, who abandoned A Baoa Qu after Gihren had been killed, would go on to give the Federation a massive black eye to prove the ghost of Zeon would live on.