"Cossacks: European Wars is a real-time strategy computer game for Windows made by the Ukrainian developer GSC Game World. It was released on April 24, 2001. The game has an isometric view and is set in the 17th and 18th centuries of Europe. It features sixteen playable nations each with its own architectural styles, technologies and units.
Cossacks: Art of War is the first standalone expansion pack.
Cossacks: Back to War is the second expansion pack, but it can be played as a standalone.
The official game sequel is Cossacks II: Napoleonic Wars."
Source: Wikipedia, "Cossacks:_European_Wars", available under the CC-BY-SA License.