Royal Presence
Q: Perhaps I am still new, and dealing with such things on a personal level, but I find myself struggling with such things as bowing to empty chairs, as I feel that it is only when they are full that they are infused with that authority.
A: We bow to the thrones, whether occupied or not, because they are the enduring symbol of the head of the Kingdom. Just as when one salutes an Officer in the military, you may or not be showing respect for that officer, but you are showing respect for the rank that officer holds.
The Thrones represent the Royal Presence even if they are empty at the time. As such it is accepted that when one passes the Royal Presence that one will make a small reverence even if no Royalty is seated at the time.
("Reverence" -- An acknowlegement of their presence. A bow (male or female), curtsy (female), doffing your hat (male), nodding your head (male or female), etc.)
Royalty also have an area around them known as the Royal Presence. This is an area you don't enter without permission. The size of this presence varies depending on the class of the royalty. In general the Royal Presence extends about 3 meters in front of the Thrones and directly in front of Their Majesties/Highnesses - seated or not. It is also considered poor etiquette to block the line of sight of Their Majesties/Highnesses.
If you wish to speak to the Royalty in question, it considered proper etiquette to stand on the outside of the royal presence until you are invited closer to converse. In some places it is proper etiquette at this time to remove any personal weapons.
Generally, do not block the view of whatever event Their Majesties/Highnesses are watching, and if you have to pass through this space, make a small, quick reverence. Also reverence the Thrones if passing within about 3-5 meters (seated royalty or empty) and if there is a high table at a feast make a reverence as you pass in front.
These rules do not apply to those carrying large, heavy, or dangerous burdens (such as banquet servers bearing hot dishes, or laden lords assisting a lady; the lady's reverence would serve for both), or those rushing to an emergency (chirgeons, marshals, parents chasing children).
If Court is in session, the Presence is normally extended to the back of the Court. The area about 3 meters in front of the thrones should be clear, as well as an aisle up the center. One should stand up when Royalty processes to and from Court, and you should make a reverence as they pass. Likewise, one should stand if the Crown/Coronet enters the room and not reseat yourself until either They sit, or leave the room.
When one is called into the Royal Presence, make a reverence as you approach. Kneel on the cushions provided, and when you leave make a reverence, and back up a bit, then turn to go. (one is not required to walk backwards the entire length of Court.)