An Envoy is a messenger from the king, arriving at player's village. It is the only character that rides a horse. An envoy presents to the player a randomly generated quest for sending resources to player's choice's destination, in effect granting appropriate influence: if to the king -- military, if to the clergy -- religious, if to the people -- labour. Player always has an option to refuse to aid any of the three sides, thus dismissing the envoy from the village. The envoy will leave the village as soon as any decision is made, and will not wait for the player to complete the quest, should one have had undertaken such.
Additionally, there are envoys specifically from the clergy, Monks, who play the same role as regular envoys. They do not ride a horse though, and are presented as a brown-cloaked praying monk.
A Minstrel is a non-interactive type of envoy that might randomly visit the player's village and play in one of player's taverns, thus inspiring player's villagers for building a randomly chosen masterpiece.