What alliance was formed by European powers in response to the threat of Napoleonic expansion?

The alliance formed by European powers in response to the threat of Napoleonic expansion is associated with the various coalitions, but the most relevant group in this particular context is the Quadruple Alliance, which included Austria, Prussia, Russia, and Great Britain. This alliance sought to maintain the balance of power in Europe following the defeat of Napoleon in 1814 and played a critical role in the subsequent Congress of Vienna.

The Seventh Coalition was indeed formed later, specifically to counter Napoleon's return during the Hundred Days in 1815. While it involved the same powers as the Quadruple Alliance, it was a temporary coalition that came together specifically to address Napoleon's escape from exile and the subsequent Battle of Waterloo. Thus, while the Seventh Coalition did respond to a direct threat from Napoleon, it was not the foundational alliance specifically created to deal with the broader threat of his expansionist policies in earlier years, which is more accurately described by the Quadruple Alliance.

The Holy Alliance, which included Austria, Prussia, and Russia, focused on a more ideological and religious unity among monarchies, but it was not a direct response to Napoleonic expansion like the Quadruple Alliance. The League of Nations, on the other hand, was