The document summarizes the challenges to the post-Napoleonic "Concert of Europe" system established by the Congress of Vienna in 1815. It discusses the wave of revolutions that swept across Europe in the 1820s-1830s as liberal and nationalist aspirations were ignored. These included the Belgian Revolution of 1830 seeking independence from the Netherlands, and a Polish uprising in 1830 against Russian rule seeking autonomy. The July Revolution of 1830 in France replaced the ultra-royalist King Charles X with the more moderate "Citizen King" Louis Philippe, though it mainly benefited the middle class and not workers.