All wars and conflicts

Seven Years' War

9 countries took part.

Read about Seven Years' War on Wikipedia

Country	Years
Austria	1756 to 1763
France	1756 to 1763
Germany	1756 to 1763
India	1756 to 1763
Portugal	1756 to 1763
Russia	1756 to 1763
Spain	1756 to 1763
Sweden	1756 to 1763
United Kingdom	1756 to 1763