One Hundred Years War

It's the battle which is told in Mobile Suit Gundam AGE

Background
150 years before the beginning of the series, Earth Federation started their Mars colonisation project, codenamed "Mars' Birthday". However, one day, due to Magnetic Ray occuring on the surface of Mars, some colonists (20% of whole colonists) fell ill. Earth Federation, considering the project as a failure, abandoned the surviving colonists and covered up the reality of project, claiming the whole colonists were wiped out of a transmittable disease; in fact, those colonists survived, but abandoned and forced to survive Mars' harsh environment. Since then, Mars' situation was never told, leaving the colonists to build their own nation not known to the other colonists in space.

Space Warring States
Some time after the new colonisation project started by Earth Federation which began the Advance Generation timeline, each colonists formed their nations, namely Euba Alliance and Zalam Union and fought each other for space domination and the war caused conflicts of every nations in space and on Earth. Earth Federation managed to bring Zalam and Euba to peace, disbanding their nations and prohibiting MSs, except for Earth Federation Forces for peacekeeping. This event was named "The Silver Chalice" which brought peace for sometime, until then...

The Day Angel Fell
In AG 101, in a peaceful colony, Angel, was suddenly under attack of an unknown force. Angel possessed no Earth Federation base, therefore, led to the destruction of Angel. Earth Federation named those invaders as Unknown Enemy. Later, in War of Bat Extermination (AG 115), the leader of the invading forces, Geera Zoi, revealed the attack was carried out by Veigan, which was once known as Unknown Enemy by EFF before Ambat. The attack was carried out because Angel wasn't protected by EFF.

War of Bat Extermination
In AG 108, another colony, Ovan, was attacked by Veigan and destroyed. The first protagonist of the series, Flit Asuno survived the attack, received the AGE System from his dying mother and went to Nora to begin constructing a mobile suit called Gundam.

In AG 115, Nora was eventually came under attack. EFF's MSs were deployed, but not matched to Veigan's more advanced MSs. It was then Flit activated his AGE-1 Gundam AGE-1 Normal and destroyed a Veigan's Ovv-f Gafran. Veigan, learning of the Gundam, sent in their colony destroyer to destroy Nora. In the same time, all Nora colonists evacuated to the colony's ejectable port and pulled out by Diva (under the command of rogue captain Grodek Ainoa). When Gundam fought the Veigan forces outside the colony, a debris held the port from being evacuated, until Commander Bruzar, the commander of Nora's base, sacrificed himself by blowing the debris in a suicide attack.

Later, Diva travelled to Fardain. There, Flit faced the ongoing battles between the remnants of Euba and Zalam, whom still fought each other even the war was ended. During the skirmish, Veigan's Ovv-a Baqtos came into the colony and Flit fought against it, but being outpowered by the much stronger Baqto and ended up being captured by Zalam's Zala, thinking Gundam AGE as an enemy trespassed their turf. While Flit kept convincing Don Boyage, the leader of the local Zalam forces to fight UE (Unknown Enemy/Veigan), leader of Euba forces Ract Elfman, came for payback. Again, in the middle of the battle, the Baqtos came back into Fardain. Flit managed to convince Zalam and Euba forces to cooperate against those Baqtos and he himself headed back to protect the truck taking the children from the Baqto. Then, AGE system gave born to the new equipment for Gundam AGE, which would later be AGE-1T Gundam AGE-1 Titus. With this new equipment, Flit managed to defeat one unit of Baqto, while the others were defeated by Woolf Eneacle's new G-Exes. After the ensuing battle, Zalam and Euba came to temporary truce to protect Fardain.

When Diva was leaving Fardain with several Zalam and Euba warships, they faced a Veigan's Fa Bose. Zalam and Euba MSs were no matched for Veigan's MSs while Diva had to deploy their forces to destroy those enemies' MSs. In the middle of the battle, Woolf and Flit faced a black transformable MS, Xvv-xc Zedas which once appeared during Nora's evacuation. Zedas had fast movements and tricked Zalam and Euba to hit each other. Don Boyage, realised with Flit's words of fighting together, decided to sacrifice himself to ensure both Zalam and Euba forces worked together with Diva forces to protect humanity. His sacrifice left a lot of lessons for those forces to fight together against Veigan. Also in the battle, AGE system produced yet another new equipment, AGE-1S Gundam AGE-1 Spallow to match up Zedas's speed. After the long battle, Veigan forces retreated with the Diva and Euba-Zalam Alliance, now under Ract's command, matched to Minsry to gather remaining Euba and Zalam forces.

In Minsry, EFF's 8th Fleet under Guabarran was commanded to arrest Grodek and Diva for discipline violation. However, the 8th Fleet was under attack by Veigan. Diva and Zalam-Euba warships protected the 8th Fleet and forced the Veigan to retreat. 8th Fleet later let Diva go to "protect the humanity". Once Diva arrived at Ambat, each sides launched their MSs. This time, Diva forces, Zalam and Euba forces were equiped with more effective weaponries and managed to defeat Veigan's MSs. After the initial strategy succeeded, Diva shot her new Photon Blaster Cannon installed by Mukured Madorna under the permission of Grodek himself and destroyed the Fa Bose, In the same time, Flit faced Xvb-xd Farsia piloted by Yurin whom was forced by Desil, who also joined the battle. When Flit's AGE-1 Spallow was heavily damaged by Desil's attacks and about to take his blow, Yurin sacrificed herself. In rage, Flit crushed Desil's Zedas, but spared him a mercy because of Desil's tearful plead. Flit then changed to Gundam AGE-1 Titus to open the Ambat's dock for Diva and changed to AGE-! Normal. Inside Ambat, Veigan's footmen fought against Diva's footmen for their last stand while Flit, with his X-Rounder ability, defeated Geera's Xvm-gz Defurse. Geera retreated to his command room and revealed to Diva's forces of their real intention and who they really are. Flit, feeling angry over the death of Yurin and his mother, wanted to shoot Geera but Geera was shot by Grodek instead. Arabel, having found out his father was mortally shot, wanted to avenge his father, before being haunted by Grodek's word. After Geera threw out his last breath, the remaining forces set up self-destruct mechanism to blow Ambat up. Diva crews managed to return to their ship in time and rendezvous with remaining forces and evacuated Ambat. After the battle, Grodek surrendered himself to EFF command for discipline. EFF, hoping to get the support from the public opinions, covered up the truth of the Diva's operation: They claimed that Diva acted independently in behalf of EFF (in fact, Diva acted independently by its own crew's wishes, not by the command of EFF) and defeated UE in Ambat. The truth about UE was revealed, but only as a nation in Mars which named Veigan and EFF didn't reveal the origin of Veigan to the public.

Operation Eden
AG 140, 25 years since War of Bat Extermination, Veigan rejected every peace proposals from Earth Federation and kept expanding its military. In the interval leading up to the events after War of Bat Extermination, Flit Asuno was married and appointed as Commander of EFF. Veigan started their Operation Eden, which Veigan would invade Earth. In the early stage of Operation Eden, a X-Rounder, the little brother of Desil Galette, Zeheart Galette was sent to Tordain, as Veigan's intelligence stated that Gundam was stored in Tordain. For his son's 17th birthday, Flit granted his son Asem Asuno (the second protagonist of the series) his Gundam AGE, hoping his son would use it to protect his beloved ones. Right one day after Zeheart enrolled to Asem's school, Veigan started their attack on Tordain. Asem had to pilot his father's Gundam AGE under the recommendation of his great grandfather, Vargas. While not having experienced with MS, Asem managed to defeat several Dorados and 1 with the assistance of the surviving EFF's Genoace II.