From the massive size of the Empire today, no one would ever guess that Solumas ever contained more than one nation. The Soluman Empire was originally a small country on the coast, mainly acting as a middleman in trade routes and negotiations. The Magi Wars changed that.
With all of its neighbors weakened financially, the small country formed mutual alliances, then eventually absorbed its neighbors. This led to a snowballing of its gains, as more nations were convinced to let the more stable nation take car of their affairs, and the young Soluman Empire now had an army to emphasize their point.
By 27 AW, one quarter of Solumas was controlled by the Empire, all gained by negotiation and minimal confrontation. The surrounding kingdoms had recovered enough to consider themselves stable again, and declined to join the growing Empire. Unfortunately for them, the government of Solumas had become convinced of the rightousness of their cause, and began to engage in military conflicts to absorb the remaining countries.
The large kingdom, now officially know as the Soluman Empire, swept through the continent in a manner of decades, finally taking Tamaril in 62 AW, and cementing its control over the entire continent. After that point, the Empire set about reorganizing and stabilizing its lands, a process which took only a decade.
In 72 AW, the Empire began to expand into Anathas. The first few kingdoms fell quickly, and for 5 years Solumas enjoyed success in forming a world government. Then, in 77 AW, they encountered the growing Valtan Empire, and clashed.
The conflict lasted centuries, though a stalemate was reached withing a few decades. During this time, the Empire refined its political system, bulding roads and organizing its member cities into a uniform layout. Their war with Valta lasted until the arrival of the Kurr'd-ah, and continues to this day, though they focus mainly on the invaders on their own continent, and have abandoned Anathas.
The Empire is ruled as a republic, with two dictators sharing power and putting forth suggestions for laws. These dictators have 10 year terms, after which the Senate elects a new pair. No person can have two terms in a row, though it is fairly common to have the same person elected multiple times. The Senators themselves are elected for life, though many step down after a few decades to make way for newer candidates. The Senate consists of 103 members at the moment, many of whom represent lands long since conquered by the Kurr'd-ah.
The Empire also claims one man as Emperor, who handles foreign policy and the military. The Emperor usually remains so for life, replaced by another Senator upon his death. Twice in recorded history the Emperor has been forced to resign due to overreaching his power, but this has not been done in over a century.
The Soluman Empire has no real allies, though they are a welcome trade partner with many nations. Valta still has a rivalry with them, and by extension, they are not well liked in Ryantra either. Still, with the halting of the Empire's expansion, Soluman representatives are treated well. Their Venatars, licensed law enforcement specializing in extradition of criminals from foreign lands, are even welcomed in Valta, and many nations have come to emulate the Empire in drafting treaties to aid in recovering dangerous criminals.