A peer is a person who holds a title of peerage. The peerage is a legal system that comprising titles in kindred society and generally mark the highest of the nobility. Nobles who do not have a formal title are Gentry.
Within Kindred society there are three main ways to become a peer. It can be inherited from life as a kine, it gain be granted by the Prince (including by indirect means for lower titles) and it can be gained through marriage.
Peers come before others in the Order of Precedence, so long as they are of the same level in society otherwise. Between peers, the order of precedence is determined by their exact title. However, the Primogen (always a Peer) always ranks above all other Peers, regardless of the exact rank.
The following ranks are considered "Peer" ranks, from highest to lowest:
Within the same rank, holders of the title come before those who married to get the title, who in turn come before any Dowager holders. Beyond this, age (from the moment of death) is used.
Peers use the Style of Lord or Lady, together with their title, rather than their last name.