The One Year War

## Belligerents

The One Year War , also known as the Zeonic War for Independence was the first major conflict of the Solar Century timeline, fought between the Principality of Zeon and the Earth Federation from January 3, 0079.

## Causes

Causes
The One Year War was the culmination of the hostilities between Side 3's Principality of Zeon and the Earth Federation. Relations between the two had been strained since Side 3 declared themselves the Autonomous Republic of Munzo under the leadership of Zeon Zum Deikun, and had only worsened since Deikun's death and the Zabi family's rise to power as the Autonomous Republic of Zeon as well as due to the Earth Federation's brutal crackdowns during the Riah Civil War and generally intolerant stance on Zeonic independence. Declaring themselves the Principality of Zeon in UC 0078, Side 3 became increasingly hostile to the Earth Federation. Zeon entered a state of national mobilization, dividing their military into a Space Attack Force under the command of Dozle Zabi and a Mobile Assault Force under the command of Kycilia Zabi. In January UC 0079, the Principality of Zeon officially declared war on the Earth Federation.

## Overview

The One Year War was the single largest and most devastating conflict of the Universal Century, in both the number of military casualties, civilian deaths, and devastation across the entire Earth Sphere. It would only be equaled years later in the Zanscare War. It began on January 3, UC 0079, when the Principality of Zeon launched surprise attacks against the Earth Federation controlled Sides. During the fierce fighting in the first weeks of the war, weapons of mass destruction were used indiscriminately, with Zeon forces deploying G3 Gas in inhabited colonies, attempting a colony drop against the EFF's headquarters at Jaburo during Operation British, and the Principality of Zeon using nuclear weapons during the Battle of Loum. During this period of fighting, each side lost nearly half of their respective populations. After this, both parties agreed to sign the Antarctic Treaty which, among other things, forbade the use of weapons of mass destruction.

## Chronology

### The One Week Battle

*See main articles: One Week Battle and Operation British*

The Principality of Zeon launched a surprise attack against Side 1, Side 2, and Side 4 on January 3, UC 0079.

Attacking a mere three seconds after officially declaring war (a fact that was sardonically referred to as the "three second warning"), the Zeon used their mobile suit forces to eliminate Earth Federation Space Forces resistance before killing the civilian inhabitants of a number of colonies with poison gas. This period of initial slaughter became known as the One Week Battle or One Week War. It was during this time that Side 6 declared its neutrality in the conflict.

The peak of the One Week Battle was Operation British, which took place on January 10, UC 0079. Zeon forces used the depopulated colony cylinder Side 2, Bunch 8 Island Iffish in an attempt to destroy the Earth Federation Forces main headquarters, Jaburo. Though the Earth Federation Space Forces dispatched a fleet of their surviving warships, and even made at least a nuclear strike, in an attempt to stop the operation, the Zeon military successfully defended the colony and the EFSF was forced to withdraw after taking near total losses. Upon entering the atmosphere, however, Isle Iffish broke apart, missing Jaburo but causing widespread destruction across Earth. The largest remaining piece of the colony, consisting of approximately the entire front half, hit Sydney, Australia, completely wiping out the city and causing massive damage across the entire continent. Operation British was a complete failure.

### The Battle of Loum

*See main article: Battle of Loum*

After the failure of Operation British, Zeon forces attacked Side 5, also known as Loum, on January 15, UC 0079. The exact goal of the Zeon forces is debated, as some sources say the fact Zeon planned another Colony drop was simply misdirection to draw the EFSF into battle, while others say it was a genuine attempt at a second colony drop, nonetheless, the operation quickly turned into a full scale fleet battle when the majority of the surviving Earth Federation Space Forces, divided into three fleets commanded by General Revil, Major General Rodney Kaningan, and Admiral Tianem counterattacked. Zeon used nuclear weapons in this battle, causing horrific loss of life not only among the combatants, but resulting in the complete destruction of Side 5 as well. The Earth Federation managed to halt the attempted colony drop and inflict significant losses on the Zeon forces but they were unable to prevent the destruction of Side 5. While the EFSF were able to evacuate a few million Side 5 inhabitants before the battle began, in the end their forces were annihilated during the battle. The Battle of Loum marked the first time that mobile suits showed their true potential in combat, proving to be terrifyingly effective against the Earth Federation fleet. General Revil was captured by the Black Quad-Stars and several other Zeon pilots (most notably Char Aznable, Shin Matsunaga, Ramba Ral, Ryan Sahalin, and Johnny Ridden) first made a name for themselves as mobile suit aces.

During the battle, a massive railgun designated the QCX-76A Jormungand was deployed. Initially not a part of the battle plan, a chance encounter between Lt. Ryan Sahalin of the Black Quad-Stars and Engineering Lieutenant Oliver May of the 603rd Technical Evaluation Unit - responsible for the Jormungand - led to Ryan providing the much needed Jormungand. The usage of the Jormungand led to devestating losses for the EFSF, as well as preserved much of Zeon's power during the battle. Nonetheless, the Jormungand and *Nereid* under the command of Rodney Kaningan destroyed each other at the conclusion of the battle, this move would become known as Kaningan's Kamikaze, and a Jormungand-Class railgun wouldn't be deployed again until the First Neo Zeon Conflict.

### Earth Drop Operations

Following the failure of Operation British and the Battle of Loum to force a decisive victory, the Zeon Armed Forces launched their Earth Drop Operations involving millions of men and thousands of mobile suits. Despite initial loses to Federation craft operating in the atmosphere, the Earth Drop Operations met with massive successes in the first months. The Zeon Earth Attack Force would manage to capture most of Asia, Europe, and North America in addition to North Africa and part of Australia, these gains would drive the Earth Federation to the very fringes of their territory, leaving them only with areas such as South America, South and Central Africa, part of Southeast Asia and most of Australia.

### Stalemate

However, Zeons rapid gains also meant that they quickly overextended their troops. Before long, the Zeon Earth Attack Force found themselves contending with supply issues, guerilla forces, and conflict between factionalized commanders incited by traditional Zabi politics. This resulted in a general stalemate with the E.F.F that would last for several months.

The stalemate would also extend to space, where Zeon's blitzkrieg had all but come to a halt and where the Zeon Space Attack Force was similarly overstretched, fighting in colonies far from Side 3 and Zeon's homeland. In space, fighting would largely become increasingly centered around Side 4, where the Moore Brotherhood would be engaging the Zeon Space Attack Force - particularly its Living Dead Division - over control of the valuable supply routes to the lunar cities, this would ultimately culminate in the "Battle Outside Riah" between the 300th Newtype Corps and the Living Dead Division. This would also see the first major engagement in which Gundam-Type mobile suits were deployed, namely the RX-78-1 and the RX-78-T1, two prototype mobile suits coming from Project V.