The One Year War refers to the conflict in the fictional universe of the anime series Mobile Suit Gundam. It takes place between the Earth Federation and the Principality of Zeon from 0079 to 0080 of the Universal Century timeline. The war is characterized by the use of giant robots called mobile suits, which revolutionize warfare. The conflict begins with Zeon's surprise attack on the Earth Federation, leading to significant battles in space and on Earth. Key events include the development of the iconic RX-78-2 Gundam and the rise of notable characters like Amuro Ray and Char Aznable. The war ultimately ends with a ceasefire, setting the stage for future conflicts in the Gundam series.