An ancestor of the modern wargames is the Kriegsspiel (Krieg for war, and Spiel for game), a Prussian game.
Kriegsspiel was one of the first known games, to try to simulate battles with a board, tokens and a set of rules, dices ...
Wikipedia will talk better than me : https://en.wikipedia.org/wiki/Kriegsspiel
And yes, 7 years war is an European war, but battles were led outside of Europe (in North America, and India). It took place between 1756 and 1763. https://en.wikipedia.org/wiki/Seven_Years%27_War
So, to sum it up, my game tries to offer a game like Kriegsspiel (but in real time), and simulates battles during 7 years war.
If it is not clear, feel free to ask me !