Later..
"Sister Celestia, what will thy sisters do for this meeting? Formal? Fun? Do we host it in thy castle before myself? Who shall we gather?" asked Princess Luna.
"Sister, that is up to you. I do not need to voice my opinion because I think it does not matter. You may use the castle, you may make it fun! This is in your hooves." said Celestia.
The leaders of Tryienne received a small letter
Dear Tryiennian Leaders,
We have prepared a meeting of our leaders. You may come, but remember there are not to be any real firearms, only ceremonial weapons or melee weapons.
-Princess Luna