The Industrial Revolution was probably the most important event, as were the French Revolution and Napoleonic Wars. Another event that had major repercussions among European intellectuals was the Greek revolt against Ottoman rule from 1821-1832. It was inspirational to many Romantic writers and painters, including Eugene Delacroix and Lord Byron, who died of illness after coming to Greece to join the rebels. Other pivotal events included the liberal nationalistic revolutions in various countries in 1820, in France in 1832, and almost everywhere in Europe in 1848.
I suppose the most profound event was the Industrial Revolution. This did more to change the everyday lives of everyone in society than any war or political change could have. After that, perhaps the two biggest things were the American and French Revolutions.
This 1772-Pre-French-Revolution painting, "An Iron Forge" by Joseph Wright of Derby, suggests to me the optimistic, Enlightenment view of technology, which the blacksmith controls for his livelihood.
Compare that to an 1801-Post-French-Revolution painting, "Coalbrookdale by Night by Philip James de Loutherbourg, showing a less optimist view of technology, which controls the blacksmith.
French Revolution, Reign of Terror, Napoleonic Wars, Rosetta Stone, Mary Shelly's Frankenstein, Jane Austin's Pride and Prejudice, first printing press in an Arabic country, Mozart, Beethoven, Barbary Wars, colonization of Africa, discovery of the cell structure of organisms, natural selection, urea becomes first person-made organic compound, railroads, interchangeable parts, Jacksonian Democracy, John Jacob Astor gets rich ...
I think that Jane Austin is not normally thought of as a romantic poet, but I think that she is a good fit with Mary Shelly something like how the Book of Judges fits with the Book of Ruth in the Bible.