Banking Icon
Assuming you already know about Coinage, you can then initiate banking. While individual units are unable to own their own property, banking improves resource exchanges between nations (known as tributes). In fact, it eliminates all fees associated with tributing.
Technology Statistics[]
Available to: All (requires Coinage)
Researched at: Market
Century: 14th
Cost: 200 Food, 100 Florins
Effect: Tribute fee eliminated.