One Year War

The One Year War (一年戦争, Ichinen Sensō?) is a fictional conflict from the Universal Century timeline of the anime Mobile Suit Gundam metaseries. The One Year War is very similar to World War II, the major difference being that The One Year War is in a science fiction setting and some major battles occurred in space. The war was originally depicted in the first Gundam anime, Mobile Suit Gundam, and later series and OVAs within this same timeline depict this fictional conflict even further.

The fictional war is also seen as a fictional depiction of a battle of social classes. Some view it as a war of wealthy versus poor.

It is the largest military conflict depicted in the Universal Century series, involving tens of thousand of mobile weapons, thousands of war ships and millions of combatants. Its casualties, both military personnel and civilians were in the billions. Series with its plot coming after this war refers to it as The One Year War or simply The War.

The war is also known as the Zeon's War of Independence to the former soldiers of the Principality of Zeon, such as in a later anime series Mobile Suit Gundam 0083: Stardust Memory and the manga Char's Deleted Affairs in which some Zeon remnants refused to admit defeat and claimed that the war was still ongoing. Some remnants continue to fight till UC0120 on Mars in the story of Mobile Suit Gundam F90, but the major conflict died out on UC0100 where the Republic of Zeon officially announce they gave up their independence.

Some speculated the war is not really a war of independence since Zeon claimed independence more than 20 years before the war began. However, official material explained that the war was a front used to stop the Earth Federation's sanctions against the new independent state because Zeon would not have the military strength to fight for the removal of the sanctions if they continued to exist.

In the current official story, the One Year War begins on January 3, UC 0079 (the Universal Century calendar begins some time after 2045 AD, according to the official timeline). A short period in the first week of the war is known as the "One Week Battle" or the "One Week War", in which most civilian casualties are accrued by the indiscriminate use of WMDs and surprise attacks.

The portion of the war depicted in the original anime, Mobile Suit Gundam depicts mainly the last few months of the "One Year War", where only the introductory narration mentioned the earlier events including destruction of multiple space colonies and the dropping of an Island 3 type colony from orbit, resulting in the destruction of half of the human population. The war ended on January 1, UC 0080, when the Republic of Zeon, reinstated after the fall of the Principality, signed a peace treaty with the Earth Federation.