1) No multi-keying, (Makes it more difficult and adds more to conversation and player interaction)
2) 1 or 2 people are the Royal chars (King, Prince, Princess etc.) everyone else is support or servants (Royal Guard, Sword-maidens, Court Mage etc, ....Wench *Lol*)
3) The Royal chars then choose who is coming with them (They create the rest of the party) example They decide on what type of char and their title, the name is still up to the other users.
4) Same kingdom is preferred. There can be an exceptions Like a traveler from another kingdom, but it must be included into the name somehow. ex: Other Royalty, Mercenaries, Foreign advisor's etc. (but remember to role-play as that i.e. don't call the royal person sire, my king, etc.) but only 1 or 2.
Then the other regular rules of CP apply. Like everyone must be present to form the party, no training without people all start at level 1 you know ... the basics.