Seven Years' War

The Seven Years' War was a major military conflict that lasted from 1756, as a result of the French and Indian War that erupted in North America in 1754, until the conclusion of the treaties of Hubertusburg and Paris in 1763. It involved all of the major European powers of the period.

The war pitted Prussia and Britain and a coalition of smaller German states against an alliance consisting of Austria, France, Russia, Sweden, and Saxony. Russia temporarily changed sides in the later stages of the war. Portugal (on the side of Great Britain) and Spain (on the side of France) entered the conflict later, and a force from the neutral Dutch Republic was attacked in India.

http://en.wikipedia.org/wiki/Seven_Years%27_War