Tiar-Shi Sphere

The Thar'shi Sphere is one of the larger historical Sangheili civilizations, born out of the merger of two large Sanghelios empires. Once a prominent political entity and the rival to the Crimson League in the Urs system, the Thar'shi Sphere is now more splintered and never became as predominant within the Covenant as the meta-culture of the Crimson League.

History
While its constituent polities emerged during the Wars of Iron and Blood, the Thar'shi Sphere itself was formed in the early centuries of the consequent space age. Thar'shi was dominated by the Kharsim ethnic group, though the Nurias played a large role, along with various smaller populations existing as vassals and dependencies.

In its heyday, the Thar'shi Sphere was an industrial powerhouse, and more centralized than the Crimson League. They expanded their territory through conquest and later economic domination of smaller polities. They controlled sizable surface holdings on Sanghelios itself, though their territory on the homeworld was smaller than that of the Crimson League. In addition to this, the Thar'shi Sphere had invested considerably in off-world holdings throughout the Urs system and later beyond, expanding its influence throughout the Sunlit Worlds in the pre-Covenant era. Owing to its centralized nature, the Sphere was famed for having the largest and most standardized standing military at the time of the War of Beginnings, but this — combined with various cultural and political aspects — also made them less flexible.

Today, the largest remaining successor polity to the Thar'shi Sphere is the Commonality of the Tiar-Sii Belt, a loose grouping of worlds located near the Sangheili core sphere unified by their historic cultural ties.