After Austria, Prussia was the largest and most influential kingdom in the German Confederation. Since the Napoleonic Wars, liberal German reformers had sought to transform absolutist Prussia into a constitutional monarchy, hoping it would then lead the thirty-eight states of the German Confederation into a unified nation-state. The agitation that followed the fall of Louis Philippe, on top of several years of crop failure and economic crises, encouraged liberals to press their demands. In March 1848, excited crowds in urban centers across the German Confederation called for liberal reforms and a national parliament, and many regional rulers quickly gave in to their demands.

When artisans and factory workers rioted in Berlin, the capital of Prussia, and joined temporarily with the middle-class liberals in the struggle against the monarchy, the Prussian king, Frederick William IV (r. 1840–1861), vacillated and then caved in. On March 21, he promised to grant Prussia a liberal constitution and to merge Prussia into a new national German state.

But urban workers wanted much more, and the Prussian aristocracy wanted much less than the moderate constitutional liberalism the king conceded. The workers issued a series of democratic and vaguely socialist demands that troubled their middle-class allies. An elected Prussian Constituent Assembly met in Berlin to write a constitution for the Prussian state, and a conservative clique gathered around the king to urge counter-revolution.

At the same time, elections were held across the German Confederation for a national parliament, which convened in Frankfurt to write a federal constitution that would lead to national unification. In October 1848, the Frankfurt parliament turned to the question of national unification and borders. At first, the deputies proposed unification around a Greater Germany that would include the German-speaking lands of the Austrian Empire in a national state. This proposal foundered on Austrian determination to maintain its empire, and some parliamentarians advocated a Lesser Germany that would unify Prussia and other German states without Austria.

Despite Austrian intransigence, in March 1849, the national parliament finally completed its draft of a liberal constitution and elected Frederick William of Prussia emperor of a “lesser” German national state (minus Austria). By early 1849, however, reaction had rolled back liberal reforms across the German Confederation. Frederick William had already reasserted his royal authority and disbanded the Prussian Constituent Assembly, and he contemptuously refused to accept the “crown from the gutter” offered by the parliament in Frankfurt. Bogged down by their preoccupation with nationalist issues, the reluctant revolutionaries in Frankfurt had waited too long and acted too timidly. By May 1849, all but the most radical deputies had resigned from the parliament, and in June, Prussian troops dissolved the remnants of the parliament.