Dawn leadership
Dawn is dominated by powerful noble houses. The houses manage their great estates and raise soldiers to fight for the Empire. Membership of a house is achieved by passing the house's Test of Mettle, although a degree of status is assumed by those sons and daughters who have been raised in a house (who are technically yeomen until they pass their test).
Each house sets its own test and only the behaviour of those who have passed the test reflects on the house. As a result a house must keep the tests difficult to maintain its reputation. Those houses that make the tests too easy face the very real risk of having no children placed with them by other nobles - no Dawn parent would want to place their child with a house that is tarnished by mediocrity.
Houses are lead by an Earl who is selected from among the members of that house. Earls usually dedicate themselves to the advancement of their noble house. It is the responsibility of the Earl to set tests such as the Test of Mettle and the Test of Ardour. The accomplishments of a House reflect directly on its Earl, an acknowledgement of the role that the Earl plays in ensuring that every member of the house is given the support they need to triumph. Likewise the bearing with which an Earl comports themselves reflects on the whole house, so Earls are expected to take their responsibilities seriously, to conduct themselves with gravitas and to expect and receive respect from their fellow Dawnish.
Some houses also choose to appoint an heir-presumptive, an individual who the house agrees will take over the Earlship if the current Earl is no longer able to perform their duties. The heir-presumptive is often a staunch ally of the Earl, someone chosen to bolster his control of the house. But the role can just as easily serve the opposite function, some nobles choose a heir-presumptive to signal the limitation of the Earl's power and what might happen if they overstretch their authority.
Only nobles become Senators or Generals, although Imperial law prevents this being mandatory. While it is theoretically possible for a yeoman to be chosen for high office, a yeoman who showed the qualities that made them eligible for such a position would almost certainly be approached by Dawnish noble houses keen to attract a rising star whose glory would reflect well on them.
The Synod and the Conclave, by contrast, are open to both yeomen and noble alike, although again a yeoman who rose to prominence in one of these structures would likely attract a great deal of attention from the Dawnish nobility.
By contrast, it is considered demeaning for nobles to involve themselves in the business of the Bourse. Making money is simply not considered glorious in Dawn, it is the business of yeoman and not something that nobles should be worrying about. A noble who spent too much time in the Bourse might cause others to question their commitment to glory and to the furtherance of their house's goals.
Leading a territory
Each territory in Dawn sends a single Senator as represenative to the Senate. To choose their senators, the noble houses compete in a grand tourney. Only nobles may participate in a Grand Tourney - Yeomen may take the field only to rescue defeated participants for medical treatment.
There is one contest for each territory, and no requirement that a candidate live in the territory for which a senator is available. The Earl of the noble house that wins a grand tourney appoints the Senator for that territory. A noble house that has won a Grand Tourney may not take part in any further Grand Tourneys while their chosen Senator is stitting,
Politics plays a role in the tourney of course, but at the end of the day this is Dawn – one cannot achieve glory by getting other people to do ones work. Several households may ally for a Grand Tourney, but in this case they all fight on behalf of one noble house. So if the House of Culwich, the House of Bardi and the House of Agaron fight as one side, they must declare before the battle which of their number will appoint the senator and if they are victorious all three of them are barred from future Grand Tourneys while the chosen Senator is sitting, A more common, if slightly inglorious, model is for an unofficial truce between powerful noble houses to clear the field of unworthy opponents, before fighting among themselves to determine the eventual winner. This tactic draws condemnation if it is uncovered, but while it is arguably against the spirit of the Grand Tourney, it is certainly not against the rules.
In theory an Earl of a victorious house could take the seat themselves, but most choose not to, preferring to leave the business of the Senate to those trained to it. The Senate offers opportunities for much glory, but they are difficult to achieve without oratorial skill, and the political battlefield of the Senate is one that is difficult for many nobles to master. Dawnish Senators are often supported by retainers who make a study of the Senate and the history of the Empire. While the nobles make impassioned speeches on the Senate floor, it is their retainers who help them prepare those speeches and work hard to ensure that the political realities of Imperial life do not scupper the nobles' plans.