Numismatic, civilian medals

Coins and medals are historical testimonies of history.
For instance many different types of coins were used during Napoleonic period.
1st was indicated "Bonaparte Premier Consul"
Then "Napoleon Empereur" on obverse and "republique française" on reverse!...with indication of napoleonic calendar, and no laurel crown on his head.
Then same but with gregorian calendar.
Then with a laurel crown.
At the end "Republique française" was replaced by "Empire Français".
After less than one year of restoration, Napoleon was back and you can find (expensive) coins made in 1815.
Each type corresponds to a change in the rules and institutions of France, you can follow them looking at these pieces of metal.