The Prince is, to put it simply, the vampire who has enough power to hold domain over a city, codify the laws for that city and keep the peace. Such a position is typically held by an elder, for who but an elder has the necessary personal charisma and power to take and hold domain in a metropolis? In some small towns, younger vampires may be able to claim domain in the same way, but their claims are rarely respected by the coteries of the cities. On occasion, strange circumstances have placed younger vampires in a position to rule cities, but few such upstarts manage to hold their titles when the elders appear.
The title "prince" is simply that - a title given to formalize a role, whether that role is held by a man or a woman. There are no dynasties of vampires holding their cities for centuries on end, no hereditary ascensions. Sometimes a prince may be called by a title native to the land he rules, such as "baron," "sultan," "count" or a less formal title such as "boss." Kindred scholars tracing the origins of the term believe that it had its roots in the Dark Ages, in reference to the lord of the manor, becoming a solid term of address after the publishing of Machiavelli's The Prince.
A prince does not "reign" over a city. His role is more like that of an overseer or magistrate than that of amonarch. He is the judge who settles disputes between Kindred, the ultimate authority on the Traditions as they relate to his city, and the keeper of the peace. Above all, his concern is the Masquerade and its preservation. Whether this means he regularly scours his city for Sabbat or keeps a stranglehold on the wilder elements is up to him. Not every prince realizes or cares that his power is meant to be so informal; indeed, some demand that they be treated like the kings of old, holding "court" and requiring that their "subjects" within the domain attend them as they pass royal pronouncements. Such arrogance can rankle the populace, both disenfranchised youth and iritated elders.
The vampire denizens of a city owe their prince no oaths of loyalty or vassalage. Their obedience depends on their cowardice, and most princes make certain to have some means of reinforcing that cowardice. If a prince's rule is questioned or thwarted, he may call in force to maintain control. However, if there is not enough force for the problem, or he finds himself without allies, his reign ends.
Having followed the protocol demanded by the Traditions, most vampires ignore their prince, or give him half an ear at best to make sure they don't miss anything that might pertain to them. On the whole, Kindred have plenty of diversions to occupy themselves with besides listening to their "leader." Some elders, Inconnu and those in a position not to care (such as Justicars) find princely announcements alternately amusing and arrogant, the blustering of a youngster still impressed with the gaudy trappings of power.
When all is said and done, however, the prince is nothing to brush off. A prince wields vast amounts of temporal power to achieve and maintain her position. Not only does she manage he Kindred affairs of a city, she usually has quite a bit of sway over mortal business. The police, the fire department, construction companies, hospitals, the mayor's office - all are extremely useful for putting own one's enemies or securing one's hold on a particular sphere of influence. If the prince wishes to squash a gang of particularly troublesome anarchs, she can have a construction company bulldoze their haven in the middle of the day. A Church-sponsored hunter operating out of a local cathedral may find the mayor's office calling to inquire about his church's tax-exempt status. Such influences usually capture the attention of those who might otherwise be inclined to thumb their noses at a prince. It is unwise to anger the one who could have your haven condemned by the zoning board or your phone line "accidentally" cut while a gas main is being dug.
Primogen
The primogen are the assembled elders of each clan in a city. Most often, each clan has a representative primogen, but in some cities a prince refuses to allow a given clan to place a member on this council of elders. In theory, primogen represent their clans among the political body of elders, but in practice the primogen are more often an "old vampires' club" and an incestuous nest of treachery and favor-currying. Primogen - the term refers to individual members as well as the collected body - convene at the prince's discretion. In cities with powerful or despotic princes, the primogen may be nothing more than a figurehead, while in other cities princes govern solely at the whim of the elder council.
It is worth noting that the prince if often not the primogen for his clan. Although some Kindred claim that having duplicate clan involved in the political structure weighs matters in favor of that clan, no one is really in a position to change it.
Sheriff
Most sheriffs are appointed by the prince and approved by the primogen. While the job description may vary from city to city, the sheriff's prime job is to be the prince's "enforcer," the vampire who hauls offenders into court, keeps order on the streets, and generally stands ready to assist with the "muscle" aspects of ruling. Sheriffs may select deputies, who occasionally require the prince's approval.
Harpies
These Kindred pride themselves on being the social managers of Elysium. They traffic in gossip and social maneuvering, and status is their coin. With the right or wrong word to a prince, they can make or break a vampire's place in the city. This position is rarely appointed outright; over time, those with the skills to be harpies tend to rise to the top. Most are unimpressed with displays of bluster and demonstrate remarkable insight into vampire nature. Bucking a harpy will assure one a place at the bottommost rung of the ladder of power for years to come.
Whip
Primogen occasionally keep whips as assistants. Not much different from the whips in mortal government, the whip's job is to goad and encourage discussion and decision-making during clan meetings, and to keep the clan updated on their primogen members' doings. Whips are selected by the primogen.
Seneschal
This is one position that many princes would like to do without, but which occasionally is necessary. One prince described the killing of this position to be akin to choosing which knife to put at her throat. A seneschal is meant to be a chamberlain, a second-in-command and an advisor to the prince. At any time, he may be asked to step into the prince's place if she leaves town on business, abdicates or is slain. Naturally, a prince wishes to have final authority on such an important position, and many have fought endlessly with their primogen over the subject. This is a dangerous position in more ways than one - familiarity with the subject can give one ideas...
Keeper of Elysium
The keeper is in charge of what goes on in Elysium. A Toreador wishing to display her latest work, a Tremere wanting to give a lecture, or a Brujah scheduling an open debate on princely policies - all must clear things with the keeper, who can cancel or approve an event on the grounds of preserving the Masquerade. The keeper is responsible for ensuring that mortals do not enter the area during Elysium and that events run smoothly. Most keepers are appointed by the prince, often with the stipulation that their appointment is conditional until their qualifications are assured.
Scourge
As the nights grow more and more violent and the cities fill with unknown Kindred, some princes have resurrected this ancient position. Essentially, the scourge patrols the borders of a princedom, seeking out and often destroying newcomers who have failed to present themselves. Caitiff, as well as the fledglings of the 13th, 14th and 15th generations, have much to fear from the scourge. In some cases, even vampires who have followed protocol fall victim to the scourge, as princes reflexively react to fears of overpopulation and espionage. A few scourges are Assamite assassins under contract to a prince.