Sangheili civil war

The Sangheili civil war was a major conflict fought between the forces loyal to Arbiter Thel 'Vadam and the Servants of the Abiding Truth in 2553 on Sanghelios.

Origins
Some months after the dissolution of the Covenant, an ancient religious order of Sangheili known as the Servants of the Abiding Truth continued to preach the divinity of the Forerunners, claiming that while the Covenant's Prophets had been false, the Forerunners were still gods and demanded reverence and respect. Consequently, they felt that Thel Vadam and those loyal to him were committing blasphemy by saying otherwise.

Assault on Vadam
In March 2553, an attempted Jiralhanae insurrection in Ontom led Avu Med 'Telcam, leader of the Servants of Abiding Truth, to the decision for an immediate assault on the State of Vadam. Along with nine ships and forces from Nuan Keep and Rtova Keep, 'Telcam commanded the assault from the frigate Unflinching Resolve. Eventually, however, the Unflinching Resolve suffered a direct hit and crash landed. Despite being caught off-guard it appeared as though the Arbiter would be victorious, however, news spread that he allowed humans to land on Sanghelios; this caused many keeps to ally with the Servants of Abiding Truth and the tide turned in their favor. The Arbiter was caught off guard and when his own reinforcements couldn't arrive on time, he reluctantly accepted Admiral Terrence Hood's offer for help in fending off the attackers. The tide turned when arrived over Sanghelios and destroyed the rebel destroyer Defender of Faith before finishing off the rebel ground forces with a MAC round. The, posed as a Kig-Yar pirate ship, destroyed a few of 'Vadam's ships in order to maintain the stalemate between the two factions, leaving the Arbiter with a Pyrrhic victory.

After the battle, Thel 'Vadam was in talks to visit the UNSC Infinity, a ship more powerful than any during the Human-Covenant War. The remnants of the Servants of Abiding Truth escaped to New Llanelli to regroup. One month later 'Telcam said he would remain on New Llanelli until he convinced more keeps to join his cause or get enough ships to destroy those who refuse.

List of appearances

 * Halo: The Thursday War
 * Halo: Mortal Dictata