What was called by at least one historian as the most momentous event of the 17th century and when did it happened?

The Thirty Years' War, which lasted from 1618 to 1648, was called by at least one historian the most momentous event of the 17th century. This devastating conflict involved many European powers and had profound political, religious, and social implications, leading to significant changes in the balance of power in Europe. The war ultimately ended with the Peace of Westphalia, which laid the groundwork for the modern system of nation-states.