The civilization with the most Envoys on a city-state, and at least 3 Envoys, is considered that city-state's Suzerain. There can be only one Suzerain; ties are not allowed. If two or more civilizations have the same number of Envoys on a city-state, there is no Suzerain.
The Suzerain of a city-state gets several significant benefits.
Unique city-state bonus[edit | edit source]
This is a powerful bonus which no other city-state will provide. For example, Buenos Aires will cause Bonus Resources to act as Luxuries and provide +1 Amenity per type, while Rapa Nui will allow the construction of the Moai, a unique tile improvement.
Visibility[edit | edit source]
Friendly territory[edit | edit source]
Inside the city-state's borders your units are "at home". They can heal there at an accelerated rate and be upgraded.
Diplomatic allegiance[edit | edit source]
The city-state will automatically follow its Suzerain into war and peace, matching the diplomatic state of the Suzerain. In Gathering Storm it will also provide +1 Diplomatic Favor per turn to its Suzerain.
Diplomatic repercussions[edit | edit source]
If the city-state gets attacked by a third party, its Suzerain will immediately gain the Protectorate War Casus Belli against the aggressor. In Gathering Storm, the Suzerain will also gain Grievances against it.
Resource sharing[edit | edit source]
All of the city-state's resources are automatically exported to the Suzerain, and the Suzerain may build tile improvements in their city-state's territory. Note that the Suzerain may make use of these resources, but may not (in the case of Luxuries) trade them to third parties.
Levying units[edit | edit source]
The Suzerain may also pay Gold to levy (i.e. take control of) the city-state's military units for 30 turns. The amount of Gold that needs to be paid is equal to the total Production cost of all military units the city-state owns.
It should be noted that levying units does not provide access to any Settlers they may have captured as those are considered civilians.
Other benefits[edit | edit source]
Kilwa Kisiwani, a Medieval Era wonder in Rise and Fall, gives its owner a 15% yield bonus from any city-state of which he or she is the Suzerain (and an additional 15% yield bonus for being the Suzerain of more than one city-state of the same type).
Related achievements[edit | edit source]
New Orleans Style Spanish Rice
Become Suzerain of a City-State.