An independent state and later empire in the Jadhai, Sira was the largest and greatest of the Nahsjad states. Founded by the eponymous tribe, the Sirans accepted the Gallatene religion of Maninism, and spread it in a religious war to the rest of the Nahsjad, uniting them and eventually leading their armies in a southward war of conquest that took the River Peko and only stopped when it met the Lovi Sea. Ultimately, the Sirans could not maintain their empire, and it split into a group of "roshates" ("Rosh" being the Nahsjad word for "successor"), the most notable being the Khivani Roshate and the Airani Roshate.
While the desert peoples were largely ignored for centuries, preoccupied with internal conflict and discouraged from all but minor raids by the powerful military of the Trilui Empire, suddenly they came out of their homeland and attacked the Trilui, becoming one of the most feared polities overnight. The Sira gained control of the Pekoan River Valley due to the lack of any appreciable military resistance.
Sira concluded peace with the declining Trilui, seeking to consolidate themselves with an uncontested claim to the northern coast of the Lovi Sea rather than risking the gains they had achieved. They didn't keep the peace for long, but their attempted invasion of the Trilui islands in the Lovi Sea floundered due to the Nahsjad's lack of seafaring skills. The blame for the disaster was placed on the Seshwaey, who at the time were assembling a new empire under the living goddess Aitah. The Sira attacked Hanno again, and the Seshweay strongholds in the Mahid, and won because of the complete lack of a comparable opposition (very likely the last time that would happen).
Because of the great distance between the Sira homeland in the northern Jadhai and the new Pekoan territories, an ad hoc arrangement emerged whereby the Crown Prince would rule the southern half of the empire from Ropoa Boa, moving north for his coronation and appointing a successor capable of managing Sira's Lovi Sea territories. It's unlikely that this system will endure for long, but under it the River Peko had been converted to Maninism. Opportunistically, the Astrii were also brought into the Faith, with the Sirans offering them protection from the expansionist Nahari Empire in return for their conversion. A series of short campaigns brought the allegiance of the Nahsjad that controlled the Jaud Narah, home to a number of Nahsjad holy sites that were quickly repurposed for Maninism.
The Empire fell to internal disputes -- the people of the interior northwest felt they were largely ignored and overtaxed by the government based in the Peko Valley. Crowning a new rosh, Airan, their rebellion triggered a series of further revolts, first in the north in the former Gallatene cities, then in the lands of what would become the Bhari Roshate. Soon enough, the south, too, broke away, and as the Siran rosh went on campaign in the north, the Peko Valley crowned a Ward, Khivan, as their new rosh. None of the competing forces had the capacity to reunite the whole, and the empire faded into memory.
The chief of a Nahsjad tribe is a rosh, and succession is traditionally decided through the Sjur Ambarrat, the heads of the clans within the tribe. The Sira typically anointed its successor (the mora) beforehand instead of after the death of the Rosh.
The ruler of the Sira, as of 184 RM, is Harran Rosh. His son, Rozzan Mora, governs the southern territories from Reppabah (Ropoa Boa for the Pekoans). Sira government is seperate for the Nahsjad vassals and non-Nahsjad subjects, with the Nahsjad continuing to operate by under their previous tribes and clan sub-divisions while owing fealty to the Rosh, while the Pekoan government is based on the Trilui civil administration and managed by the Mora.
A seperate religious hierarchy exists of Maninist Wards, but under the authority of the Sira Rosh instead of the High Ward. The Wards are required to have become Nahsjad jaudarah (from completing a pilgrimage to the Jaud Narah) in addition to the usual Maninist requirements, resulting in few native Pekoans rising within the Sira priesthood.
Lancers and horse archers recruited from among the Nahsjad, largely horse but with a sizable (though declining) camel contingent. Spear and bow infantry are largely drafted from the Pekoan population, and used as garrisons or support. The Nahsjad soldiers have a Kyatay Ambarrat, or warrior's council, from which commanders are typically drawn.
The navy is almost exclusively a Pekoan affair, as Nahsjad naval incompetence is legendary. It uses fast and nimble jachts suited for patrol and pirate-hunting within the Kasud Narah, and is reliant on converted merchantmen for its heavier ships.