Obsolete With: Automobile
Cost: 400 Shields
Whenever a unit becomes obsolete because of new technology you have discovered, Leonardo's Workshop immediately replaces it with an equivalent (though not veteran) modern unit. When you acquire a city by bribery, any remaining units that are obsolete for you get upgraded immediately.
Note that players with veteran Pikemen (defense strength 6 against mounted units) may regret their replacement by non-veteran Musketeers (strength 3)! That could be a reason for not going out of your way to discover Feudalism or build Pikemen if you expect to get Gunpowder soon.
Leonardo da Vinci was one of the most celebrated painters of the Italian Renaissance. His most famous works include the "Mona Lisa" and "The Last Supper". Although best known for his art, da Vinci was also an accomplished observer and designer. Preserved in his sketch books are ideas for dozens of inventions, many of them centuries ahead of their time. These include designs for such devices as draw bridges, construction equipment, parachutes, and even helicopters. His scientific and technical drawings became the basis for the development of many of these modern devices.