I couldn't find any other threads about envoys so sorry if this has been covered elsewhere.
We now know that envoys are generated by the influence points generated by our government (and a few other sources such as cards). But once you've got an envoy and you've sent it to a city state, do we have the freedom to remove and reallocate those envoys or once they are sent do they stay with the same city state all game?
What if the city state is conquered, if envoys can't be removed are those ones lost?