In contrast to Mercenary Gunners, which are hired from other countries, Bohemia, Flanders and Savoy build their own domestic artillery in the 15th century. With the research of Alchemy, these countries are able to found cannons of the same quality as the mercenary artillery, but at comparably cheaper costs. They require a decent amount of wood, but less florins than their mercenary equivalents.
Domestic Artillery:
Bohemia: Houfnice
Flanders: Donderbusse
Savoy: Culverine