Baron / Baroness
Barons and Baronesses
There are two types of Baronies in the Society: Landed and Court.
Landed Baronies
Landed, or territorial Barons and Baroness rule over a Barony in the name of the King and Queen. They provide a visible ceremonial presence, representing Royalty within their Barony. Conversely they provide a representation of the Barony at Crown events elsewhere in the kingdom, through such activites as the Grand Procession at Crown Tournaments, the swearing of fealty on behalf of the Barony at Coronations, etc. They are also expected to advise the Crown as to the state of their barony, both the good and the bad, and during their tenure in office are considered part of the Noble Estate.
Depending on the barony in question, Barons and Baronesses may or may not have some real-world authority insofar as the governance of the Barony is concerned. In An Tir it is a requirement of the Kingdom Financial Policy that the ruling Baron and Baroness be signatories on the barony's bank account(s).
For a list of the people who have been Landed Barons and Baronesses see Category:Territorial Barons & Baronesses
The OP list of current Royals, Offices, and Positions. (Includes current Landed Barons and Baronesses)
Court Baronies
A Court Baron or Baroness is made so by the gift of the Crown. In An Tir, it is considered the second-highest honour the Crown may grant. Usually when a landed Baron and Baroness retire from their position, the Crown will confer the title of Court Baron and Baroness upon them in recognition of the sustained effort required in the office.
A Court Barony also confers an Award of Arms, if the recipient is not yet armigerous.
A listing of Court Barons and Baronesses.
Usage and Address
Barons and Baronesses, of either type, may use the title "Baron" or "Baroness" in front of their names. They are properly addressed as "Your Excellency" and are properly referred to in the third person as "His/Her Excellency."
Court barons and baronesses may also be addressed and referred to in the third person as "Baron/ess [personal name]".
The ruling Baron and Baroness of a barony may also properly be addressed and referred to in the third person as "Baron/ess of [branch name]".
NOTE: The first Baron and Baroness of a barony, upon their stepping down from the office, may style themselves in perpetuity as "Baron/ess [branch name]" (note the missing "of"). Succeeding ruling barons and baronesses do not enjoy this privilege.
Examples
Regina Romsey, among other things, is a Court Baroness, has been a ruling Baroness and is a founding (first) Baroness.
She received a Court Barony in the Kingdom of the East, and thus could be correctly referred to as "Baroness Regina" or "Regina, Baroness of the Court of the East".
When she assumed office as Baroness of Knights' Crossing, it was then correct to refer to her as "Regina, Baroness of Knights' Crossing."
When she stepped down from that office, since she was the first Baroness, she was then entitled from then on to style herself "Regina, Baroness Knights' Crossing."