Halo Alpha
Halo Alpha

Sunaion was a city on the Sangheili homeworld of Sanghelios. The city was situated above the Csurdon Sea[note 1] and kept up by large columns.[2]



Sunaion was originally stone fortresses on the coast of Nuusra. It was founded by ancient Sangheili elders after dive-hunters and fishing skiffs found a Guardian in the sea. It was officially named Sunaion centuries later, when a temple was established on pillars over the site in the sea.[1]

Historic Usage[]

For a long time, the Covenant Empire used the site to explore and worship the Guardian. Besides a few anchorites, the Human-Covenant war caused the city to mostly remain empty.[1]

Immediately after the war, the city was left neutral. Eventually revolutionaries would see it a good staging ground to attack Yermo and the rest of the State of Vadam.[1]

Covenant Occupation[]

By 2558, Sunaion had been captured by Jul 'Mdama's Covenant and turned into a major stronghold.[2] The Remnant planned on attacking the State of Vadam from here, however the Arbiter Thel 'Vadam learned of this plan. The Swords of Sanghelios created an outpost in Nuusra and planned on eventually striking the city.[1] When Jul 'Mdama was assassinated, the remaining Covenant forces gathered at Sunaion.[3]

Battle of Sunaion[]

H5G BattleofSunaion

Thel 'Vadam's Lich moves through the skyline of Sunaion.

“Swords of Sanghelios, today Sunaion will fall, and with it the Covenant!”
— Thel 'Vadam during the Battle of Sunaion.[2]
Main article: Battle of Sunaion

Sometime in late October 2558, Sunaion was attacked by the Swords of Sanghelios in an attempt to end Jul 'Mdama's Covenant. At some point in the battle, Fireteam Osiris was deployed into the city by Thel 'Vadam's Lich and was tasked with reaching the activating Guardian buried below the city. The Swords won the battle and with the help of Sarah Palmer, Osiris boarded the Guardian and was taken to Genesis.[2]


There were two levels to the city. There was an upper level featuring large plazas, temples and other such buildings. Below that was an undercity that was incredibly close to the waters of the sea. Elevators were used to reach this lower area.[2]


Concept Art[]




  1. While not stated in the article itself, this is mentioned in Canon Fodder - Sending Out an SOS link to Sunaion and mentioned in Sunaion's panel within the Locations section of Waypoint.