Battle of Netherop (2559)

The Battle of Netherop occurred after the discovery of an ancient weapon that destroyed a Guardian Custode was made. An operation on Netherop to claim it started a conflict between the UNSC and the Swords of Sanghelios, the Banished, and Nizat 'Kvarosee's faction which was made up of surviving rogue Covenant soldiers exiled on the planet in 2526.

Netherop
During the Forerunner-Precursor war, Precursor fugitives took refuge on the planet Netherop with the Tier 6 civilization already inhabiting it. When a Guardian Custode attacked, the Precursors used their weapon, the Divine Hand, to destroy the Guardian. However, the weapon also destroyed the local civilization and the planet, turning Netherop from a lush inhabitable world into a barely inhabitable wasteland.

In 2526, Netherop was the site of two battles between the United Nations Space Command and the Covenant, specifically a rogue faction led by Fleetmaster Nizat 'Kvarosee who sought to destroy ONI after his humiliation in Operation: SILENT STORM, seeing them as the greatest threat to the Covenant. However, Nizat's rogue actions led to the Hierarchs sending a fleet to stop him, leading to the destruction or retreat of the Flotilla of Unyielding Piety. Nizat and his ground forces were exiled on Netherop's surface with an orbital mine shell being placed in orbit of the planet in order to prevent anyone from coming back for him. In addition, Lieutenant Commander Amalea Petrov and some of her forces were left stranded on Netherop as well. Over the next thirty-three years, the UNSC and Covenant survivors fought each other, resulting in the death of most of Nizat's forces, leaving only Nizat himself and six others while the humans numbers continued to grow as the stranded survivors had children and families.

The Created
In October 2558, a force of artificial intelligences known as the Created, led by Cortana, alongside an army of Prometheans, rose up and began to subjugate the Milky Way galaxy. A year following this rise, the UNSC and their Sangheili allies were still trying to find a way to stop Cortana's rule. An xenoarchaologist, Keely Iyuska, was interested in learning and study the remnants of an ancient non-Forerunner civilization on the planet Netherop, site of a battle between the UNSC and the Covenant decades earlier. When the Created rised, she couldn't realise her plans. On November 2559, however, Iyuska was contacted and founded by a benefactor to study Netherop and its technology. During her studies, Iyuska managed to find records indicated that a Guardian Custode was sent to subdue Netherop, and that the planet's civilization had managed to defeat the construct. Instead of informing her benefactor, Iyuska travelled to Sanghelios and inform Spartan Olympia Vale about her discovery.

The Banished
During his time on Installation 00, Atriox was able to find records on a crashed Phaeton about an ancient weapon on Netherop that managed to destroy a Guardian Custode. Months later, during Operation: WOLFE, Atriox was able to return to the Milky Way via a portal complex under the Menachite Mountain on Reach, were he started his plans to claim the weapon on Netherop and then start his campaign to take Installation 07 from Cortana. To further their plans, Eto 'Saljhoo funded Keely Iyuska's investigation about the former civilization on Netherop, with the condition that any artifacts Iyuska would find, it would be delivered to him. When Iyuska didn't hold her promise, 'Saljhoo hired the Oath Warden Crei 'Ayomuu to track Iyuska. Weeks after the Warmaster's return, Cortana tried to summit Atriox and the Banished under her command, with no success; in retaliation, Cortana used her Guardian Custodes to destroy Doisac and its moons.

List of appearances

 * Halo: Outcasts