In general, Gloranthan kingdoms and empires send representatives to each other’s countries to negotiate on specific issues, such as war, peace, or trade relations. Sometimes, a high status member of one kingdom resides in the capital of another to serve as a permanent representative – unofficial or not.
In Boldhome, there is an entire section of the city that has been given over to rich foreigners. Several permanent residences or embassies are maintained:
Feathered Horse Queen Palace – this complex of buildings was built by King Sartar for his wife, the Feathered Horse Queen, although she only visited here once. It is now home to the representative of the Feathered Horse Queen in Boldhome and her household, bodyguards, and servants.
Tarsh Palace – This is the embassy for the representative of the King of Tarsh, or more precisely, whichever king is recognized by the Prince. The Lunar kings were long denied recognition; instead this was home to a representative from the Shaker Temple or Wintertop. After the city’s conquest by the Lunar Empire in 1602, the Lunar kings reclaimed this building and impressively rebuilt it. It is now the residence of Estal Donge, sister of King Pharandros.
Queen’s Palace – This high and magical tower rises 50 meters above the surrounding valley. A huge stone serpent winds around it and protects its inhabitants. This was the embassy of the God-King of Kethaela, an important ally of the old dynasty. During the Lunar Occupation, it was nearly abandoned (although the Lunars never tried to violate it), but now has been reclaimed by the Queen of Esrolia who has recently sent a representative from Nochet.
Inviolate Dwarf Palace – On the cliff face hangs the Inviolate Dwarf Palace, very solid and yet so well constructed that it seems part of the mountain. It was here when Sartar first discovered the valley. The dwarves were great friends of Sartar, and they built the best and most beautiful parts of the city. Lord Golden the Dwarf King resided within, enthroned in a hall where mosaics were made of gems. His servants were made of bronze, and his guards made of stone. But the friendship between House of Sartar and the Dwarf King mysteriously ended during the reign of Prince Saronil. The dwarves sealed up the palace from the inside and have not been seen since.
So it is worth thinking about who ends up being sent as the emissary. Certainly not a “professional diplomat” – kingdoms and empires are family matters, not impersonal “states”. Typically an emissary is a family member or trusted companion of the ruler, or someone chosen by the ruling body of a city.
Upon becoming Prince, Argrath sent emissaries to Nochet and the Feathered Horse Queen – these were both trusted companions. With Furthest, he used the Issaries cult as messengers (and some claim as spies), and also worked through various kinsman of King Pharandros.