Ambassador

An Ambassador a member of a House who is sent to attend the court of another House.

Codex
"A member of a house that is assigned to diplomacy can also be sent as an ambassador to another house, where they will act as a representative, apologist, and spy.

An ambassador within another house is far more effective at positively influencing opinion towards their master than the more passive propaganda of diplomats kept at home. Ambassadors cost their sending house a small amount of money each turn to support.

Once an ambassador is established, it is an insult to either recall them or expel them, unless they need to return home for a legitimate reason, or unless they are immediately replaced by another ambassador."