The battle of Plassey and the taking of Quebec are conventionally accounted part of the Seven Years War. However properly speaking the Seven Years war was a Middle-European conflict between Prussia and Austria in which France became directly involved as an ally of Austria and the German state of Hanover as an ally of Prussie. Since the Elector of Hanover also just happened to be the King of England it was inevitable that some of his British troops should find themselves sent to fight in the great war in High Germany; but British and French troops had already started fighting long before in quite unrelated conflicts across the Atlantic and on the far side of the world.
Although there had already been some earlier skirmishing between local forces, the British government’s decision in 1754 to for the first time send two battalions of regular infantry to North America and one battalion to India provides a logical starting point, for the French immediately responded in kind and thereafter the rather desultory character of warfare in both theatres changed dramatically.
Nevertheless the armies of Britain and France which fought overseas in those almost private wars differed in significant ways from those which faced each other on European battlefields.