The Lord Commander is the leader of the Song Dominion, both in government, culturally and - in some people’s eyes - spiritually. None have higher authority within Song’s borders than the Lord Commander, save for the next person who has enough social influence to supplant the current leader.
History
At the end of the 40-year Empire War, the economy of the Song Dominion, like the Celestine Ascendancy, was ruined. Famine swept through parts of the Dominion, and in order keep order, their battered military asserted control and supplanted the formerly-civilian and heavily-corrupt government in what is officially known as the Restoration.
The military leadership, led by what was then called the Grand Admiral - an Amaian man named Adyos Endatia - effected a bloodless coup, displacing and exiling the civilian leadership with the support of a large portion of the populace.
Adyos had been a hero in the Empire War and was easily the most-admired person in the Dominion at the time. The people had enough of the grasping, petty nature of politicians and were glad to see a strong leader who would do what he had to to protect and elevate the Song Dominion.
In joining the role of the military and the government, a new, supreme position in the Song Dominion was created: the Lord Commander.
Of course, not everyone supported Adyos's rise, and for the good of the Dominion, those who felt the need to carry on about their dissatisfaction, especially in public, were soon silenced or left the Dominion, for Scatterhome or elsewhere.
Adyos looked at the landscape surrounding himself and saw himself an island in a dark forest filled with predators.
First and foremost, of course, was the Celestine Ascendancy, though they'd been as weakened as the Song were by their protracted struggle, but there were any number of civilizations that might choose to strike, from the Vonikin Krel to the Fatar or Selassians to the ever-lurking threat of the Ishvana and its subject peoples.
He and his advisors believed that they must, immediately, begin to rebuilt the power of the Dominion, and that nearly any sacrifice was acceptable if the end result was achieved. Piracy, or "strategic confiscation" became an unofficial policy and, as the Dominion grew stronger, an official one. Unions were outlawed, as were mass protests. Slavery was legalized, and became the standard punishment for those engaged in open dissent against the office of the Lord Commander, for what better way to signal oneself a traitor than to stand in opposition to the Hero of the Dominion?
Time passed, and eventually Adyos died of natural causes. Who would supplant him as Lord Commander? He had never established a succession plan, preferring to let his lieutenants fight amongst themselves for his patronage. It is here that the root of the Song Dominion's modern form of government took hold.
It was decided that all military officers would have a say in choosing the next Lord Commander, but instead of anything so egalitarian as one-person-one-vote, each officer would, according to their rank, receive a different number of "votes" to cast in what became known as a Challenge. Under this rough system, the next Lord Commander was selected - a female Ry'nari admiral named Henar Kelaka.
As the decades passed, the military's influence spread throughout all of the Song Dominion, until it was no longer possible to reasonably separate where society began, and the military ended. The entire society was armed, and all able-bodied adults were required to serve a two-year stint in the armed forces. Private militias, loyal to the State, were formed to defend the Song, usually composed of small fighter craft with perhaps a corvette or even destroyer anchoring that cell. The Lord Commander, whoever it may be at the time was lionized and was considered not just the peoples' political and military leader, but in many ways a spiritual leader as well, embodying the best of the strength, resilience, and will to power that marks the Song Dominion.
The system of selecting the Lord Commander slowly changed as well, until it arrived at today's system, wherein citizens gain Influence by performing actions that help the Dominion and can then spend that Influence on a Challenge to replace the Lord Commander with a new one. The more useful that citizen is, the more Influence they have, and thus the more say in appointing a new Lord Commander.
That is, however, the only direct say the citizens of the Song have, for the Dominion believes in unity of purpose and unity of mind. Near-total power is exercised by the Lord Commander, at their discretion, though an incompetent or corrupt Lord Commander is likely to find themselves quickly replaced by the powerful amongst the citizenry.
The Lord Commander at the time of Starmourn's opening (921 A.E.) was a female Amaian named Veria Quaeos, who took the position in 908 A.E