War of the Grand Alliance
In Look to the West, this war is also sometimes called the 'Zeroth War of Supremacy'. Other alternative names are the Nine Years' War and King William's War.
The war took place before the timeline's POD, but is nonetheless worth noting here because it sets the scene for the 18th century. This was arguably the peak of royal French power, when the Kingdom of France under Louis XIV took on virtually every country in Europe and fought them all to a standstill. It also represents the birth of England, later Great Britain, as a great power, when the unpopular regime of James II was swept aside in the Glorious Revolution of 1688 and William of the Netherlands became William I, ruling jointly with his wife Mary II, James' daughter.
The war and revolution determined 18th century British political culture, seeing the collapse of the pro-Stuart Tory party at Westminster, the instigation of populist anti-Catholic policies in the Constitution of 1689, and the brutal suppression of pro-Stuart Jacobitism in Ireland. However, the Constitution also solved the unhappy conflicts between crown and parliament which had dominated the seventeenth century in the British Isles, and was widely seen thereafter as the epitome of English liberty (providing you were an Anglican).
In a parallel, Louis XIV of France revoked the Edict of Nantes that guaranteed tolerance of French Protestants, the Huguenots. Persecution resumed and many Huguenots fled to England, where they influenced the culture of London and contributed much to both English industry and the armed forces.
This was the first European war to spill over into the North American colonies, and saw initial great successes on the part of the English colonists (the later Americans) before defeat and retreat in an ambitious campaign aimed at conquering French Canada.