Fall of High Charity

The Battle of High Charity was a large battle for control of the Covenant Capital, High Charity. The battle was significant in that it was the start of the Covenant Civil War, and contained hunts for both the Index by Spartan-117 and the Flood Invasion of High Charity

The fracturing of the Covenant
The Battle of High Charity was one that would have happened eventually, for it was the point of origin for the Covenant Civil War. With the Brutes slowly gaining the favor of the Prophets over the Elites, it was only a matter of time before the actual split would happen.

This was further helped along by the Changing of the Guard, giving the Brutes the position of being the personal protectors of the Prophets, and the failing to protect both Installation 04 (Alpha Halo) and the Prophet of Regret.

Battle of Installation 05
However, while the eventuality of the Battle of High Charity was a foregone conclusion, its scale was not. The Prophet of Regret's wayward mission to Earth brought High Charity, Spartan-117 and In Amber Clad near Installation 05. With the Gravemind already released and plotting its way off of the Halo, this would set the tables for the invasion by both the Flood and the legendary "Demon".

The final piece of the puzzle in the battle was when Tartarus took the Sacred Icon from the Arbiter and subsequently attempted to execute the latter.

Gravemind
The Arbiter, however, would not be slain there. The Gravemind had other plans for him along with Spartan-117. Realizing that the Index, now in the hands of the Covenant who fully intended to fire the Halos, would result in his death, the Gravemind saved both of their lives from being killed so that they could aid him in finding and recovering the Index. With two plausible locations for the Index being High Charity with the Prophets and the Control Room on Halo, he send Spartan-117 to the former and Arbiter to the latter.

The Battle
The fight began during the Covenant civil war. The Master Chief was transported there by Gravemind using Delta Halo's teleportation system. Meanwhile the Civil War Raged and while Master Chief rescued some Marines, the Flood managed to take over In Amber Clad and warp jump into High Charity. The Flood then took over all the Pelicans using brain forms and spread out over the station. Loyalists and Separtists battled each other and the Flood, while Master Chief fought his way to a fuel cell to enter the Forerunner Ship in the middle of the city, and find Truth. The Flood finally won control over High Charity and Gravemind Teleported onto the ship. Cortana stayed on High Charity and her fate remains unknown.

Covenant Civil War
The Battle became the starting point of the Covenant Civil War. Warships around High Charity continued to fight well after the battle was over. However, whether the battle's outcome would have any lasting impact on the outcome of the Covenant Civil War is currently unknown.

Tartarus and the Index
Tartarus would eventually make it to the Control Room with Miranda Keyes and begin the firing sequence for Installation 05. However, the Chieftain would eventually fall and the firing sequence canceled, putting all Installations into standby mode.

The battle would be the starting point for the alliance between the Covenant Seperatists and the UNSC.

Prophet of Truth and Spartan-117
The Prophet of Truth and Spartan-117 would eventually join the Second Battle of Earth aboard the Forerunner ship. Admiral Hood initially ordered the ship to be destroyed, but Spartan-117 identified that he was aboard the ship and wanted to Finish the fight.

High Charity
The Flood eventually gained full control of High Charity and the Gravemind would take up residence in the fortress. However, the fortress was disabled with the decoupling of the Forerunner ship, without powered and likely unable to move. Cortana, stranded in High Charity's computer, would be questioned by the Gravemind.