The Sontaran Dominion is the interstellar, interplanetary government controlled by the militaristic clone race of Sontarans.  Non-Sontaran races are considered to be second-class citizens, but non-Sontarans can raise their social status within the Dominion if they serve in the Dominion military or police forces for a five-year term of service. 

Government in the Dominion is vested in the Sontaran clone Emperor, whose very word is absolute law.  The Emperor is aided by a Council of Advisors, mostly Sontaran military commanders, although a few, rare, trusted non-Sontarans have served on the Council. 

The government of planets is vested mostly in governors appointed by the Emperor or his Council of Advisors.  Planetary governors are mostly Sontarans, although a few rare non-Sontarans have been appointed planetary governor in Dominion space. 

The Doninion has waged many wars with Orks, the New Shi'ar Imperium, the United Pirate Clans, the Systems Commonwealth, the Cylons, the Kurgan Caliphate, and other factions.

Perhaps surprisingly, some non-Sontarans welcome Sontaran rule.  In certain cases, it's because non-Sontarans want to retain religious freedom (which the Dominion actually promotes in the case of non-Sontaran subject populations) and want to be free of the Kurgan Caliphate with it's fanatical state religion and forcible conversions.  In other cases, it's because Humans want to escape the genocidal purges of Cylon robots based on New Cylon.

Not all of the populations under Dominion rule support the Sontaran regime. There have been some elements of armed guerrilla resistance.

Orks hired by the Dominion as mercenaries have a friendly rivalry with the Dominion's regular Sontaran soldiers.