It is the year 0079 of the Universal Century. The colonies of side 3, the furthest from the Earth have declared themselves the Duchy of Zeon and have launched a war of independence against the United Earth Government. 

During the battle in the first month, both side lost half of their respective population. All mankind was horrified by the atrocities it committed.

The battle had been dragged for over 8 months...

During these months, the Earth United Government suffered heavy casualties due to the Zeon's new developed weapon, the mobile suits. Because of a new discovery of the Minovsky particle, a special particle that would jam all radar and radio, all long range, conventional radar guided missiles were impotent. Therefore, the small scale, humanoid, short-range combat vehicle were able to create a devastative effect to the Earth United Government's space fleets.  

However, during the war, the Earth United Government also developed their own mobile suit. Several of them were being tested at the side 7 colony cluster. And during these prototypes, one was activated during the Duchy of Zeon's sneak attack, and its power  was able to change the balance of war, and the name is Gundam. 

Synopsis 
Gundam Movie I
In the year 0079 of the Universal Century, the Earth Federation and its space colonies are engaged in an apocalyptic war. The rebellious Duchy of Zeon, using humanoid fighting machines called mobile suits, has all but vanquished the Federation. Now the Federation's last hope is the prototype mobile suit Gundam. When a twist of fate makes young civilian Amuro Rey the Gundam's pilot, his own battle begins - a struggle not only for the Federation's survival, but for his own.

Gundam Movie II
The Federation space ship White Base and its precious cargo of prototype mobile suits have returned to Earth, only to find themselves in enemy territory. As the White Base struggles across the planet's surface to safety, Gundam pilot Amuro Rey must contend not only with the Duchy of Zeon's fiercest warriors, but also with his own doubts and fears.

Gundam Movie III
With the conflict's end in sight, the Earth Federation prepares to take the war into the Duchy of Zeon's home territory. Gundam pilot Amuro Rey, now a seasoned veteran, returns to space for the final battle. Here, he will meet the mysterious Lalah Sun, a young woman who shares his Newtype abilities. Amuro's adversary Char Aznable seeks to complete his secret quest for vengeance. While their fates intertwine with tragic consequences.