+2 Influence Points per turn. Gain +1 Envoy.
+1 Spy and Spy capacity.All Spy Operations have a higher chance of success.
Your Spy units gain +2 sight range, Spy mission time reduces by 15% and have a free promotion and can choose from any possible promotion.
All units gain +3 Combat Bonus from each level of Diplomatic Visibility.
Can only be built once in a civilization.