The Seven Years War (1756-1763) was a war that involved every major European nation and was fought across the world.
The Seven Years War started when Austrian Empireball tried regaining Silesian clay from Kingdom of Prussiaball. UKball allied with Kingdom of Prussiaball, which led to Kingdom of Franceball allying with Austrian Empireball. This lead to basically everyone joining and fighting in Europe. Thanks to colonialism, Native American tribes and even Mughalball joined the war.