The Kingdom of the Drow is the territory where most of the Drow reside, deep in the northern part of the Elven Realm. It consists of the Banished Houses of Elves that were corrupted by the overuse of Dark Magi, turning themselves into Drow. Formerly ruled by a king chosen from the various banished houses, the king was slain by Nasgi Ezrath in a military coup d'état ten years after the Lightwar. Ezrath is now the current Queen of the Drow Kingdom.
The history of the Drow Kingdom begins with the union of the corrupted Elven houses following their expulsion from the heart of the Elven Realm. They gathered in the north, at the border of the Northern Wastes, and decided to form a monarchy to govern themselves. Shedding the rule of their Elven breatheren, they named a King and Queen from among them and began for form laws for governance. They also conquered and claimed land, forming a small kingdom to rule over.
Beyond spats with the Elves and those that would wander into the Drow Kingdom from the north or south, it was rather quiet in the Kingdom. The Drow continued their experimentation with dark magic, further corrupting themselves into what they are today. Eventually, Kodan the Dark would visit the Kingdom and convince the various houses to join him in his future campaigns.
After the Lightwar, the Drow returned home to what they had been doing before. Most of them anyway. About ten years after the war, the dark battlemage and necromancer Nasgi Ezrath staged a coup, overthrowing and killing the Drow King at the time. She killed off the rest of his family afterwards, and claimed the title of Queen of the Drow for herself. Ezrath has remained the Queen for going on twenty years now, ruling over her subjects with an iron fist...and eyeing ravenously the Elven Realm to the south.
The structure of the Drow Kingdom is pretty much like that of your standard Monarchy. The Drow King/Queen sits at the top, and has absolute rule over the entire kingdom. He/she makes the laws, listens to their advisors, orders around the military forces. Typical royal duties. Traditionally, a king/queen was chosen from among the Drow Houses, but that changed after Ezrath killed the current King and assumed the throne herself.
Beneath the King/Queen are the Royal Advisors. Their word is almost as powerful as that of the ruler themself, as they act as his/her hands. Usually, one is chosen from each of the houses, as to properly represent them all. They oversee operations in the kingdom and deliver reports to the ruler. They also see that orders from the ruler are carried out.
Beneath the Advisors are the Royal Guard and Drow Military. As with most other militaries, they carry out their ruler's orders and enforce their will on either the citizenry or upon opposing forces. They defend the kingdom (or make it bigger) in the name of the Drow king/queen. The Royal Guard are tasked with defending the king/queen from danger, though Ezrath is quite capable of protecting herself.
Next are the Drow citizens. They vary amongst their skills and occupation, but all are loyal to king and country. Despite their personalities and physical state (and their ownership of slaves), they are much like their Elven counterparts in the way they conduct their lives.
Beneath everything else are the slaves of the Kingdom. Either captured in battle by the Drow Military and sold to the citizenry, or taken by the Drow citizens themselves, They vary in race, and are used for anything from hard labor to sex. They have practically no rights or sayso in their lives, as the Drow would more than likely kill them first.