Frederick William IV., son and successor of the preceding, born Oct. 15, 1795, died at the chateau of Sans Souci, near Potsdam, Jan. 2, 1861. He received a careful scientific education, though his boyhood was passed in the most disastrous period of Prussian history, and his youth in that of the great struggle against Napoleon. He was often present on the scene of action during the last campaign against that emperor, became familiarly acquainted with many distinguished men of his age, and developed his taste for the fine arts while residing in Paris after its occupation by the allies, and on a journey to Italy in 1828. Admitted to the councils of his father, he evinced a marked independence of opinion with much administrative ability. As military governor of Pomerania, his affability gained him general popularity. He succeeded to the throne June 7, 1840. His first solemn declaration at Konigsberg, a limited political amnesty, the reinstating of Arndt, the old liberal poet, the reappointment to office of the popular lieutenant general Von Boyen, and the conciliatory termination of a difficulty between the state and the Roman Catholic clergy, were hailed with applause; but the appointment to office of Hiassenpflug and Eichhorn, and various other conservative measures, soon destroyed the hopes of the liberal part of the nation.

The development given to the representation by provincial estates, which had been introduced under the preceding reign, by the convocation of their standing committees in 1842, and by the convocation of the united provincial estates of the kingdom in February, 1847, was made less significant by the distinct declaration of the king that the representatives, far from becoming legislators, would be allowed only to give advice to the unlimited sovereign, and that he would never consent to bind his inherited authority by a written compact. Periodical meetings of the united assembly were asked for in vain. The government, though granting general toleration, declared against the separation of the church from the state and the emancipation of the Jews, and avowedly sought to rule the kingdom in conformity with the views of the school generally known as pietists. Much more was done for the material interests of the state through internal improvements, commercial union with foreign states, and the extension of the Zoll-verein, which also augmented the political influence of Prussia. A bank with a capital of 10,000,000 thalers was established at Berlin. The Polish conspiracy of 1846, which threatened the eastern possessions of the king, was detected in time in the duchy of Posen: the outbreak in the same province was easily suppressed; the insurgents of Cracow, who laid down their arms on Prussian territory, were treated with rigor.

The people were already politically agitated by the lively discussions of the diet (from April 11 to June 26, 1847), and of its standing committees, assembled Jan. 18, 1848, and also by the trial of the insurrectionists of Posen, and of Miero-slawski, the destined leader of the Polish move-ment, as well as by the victory of the liberals in Switzerland over the Sonderbund, the constitutional movements in Italy, and the revolution in Sicily, when the news of the French revolution of Feb. 24 involved the whole of Germany in a flame. The popular movement was victorious all over the southwest and south of the confederation, before FrederickWilliam was forced to yield to it. Even after the fall of Metternich in Vienna (March 13), he was determined to maintain his royal authority, and to grant liberties only as free gifts. Threatening popular gatherings in Berlin were dispersed by his soldiery before he proclaimed the freedom of the press and the promise of a change in the form of government. These concessions were received with enthusiasm, but the people still demanded the removal of the troops from the capital, and for this purpose a deputation of citizens visited the palace (March 18), while a crowd assembled before it.

The deputation was refused admittance, and soldiers advanced from the court of the palace to clear the place. Some shots were fired, and the people dispersed in every direction with cries of '"Treason! they are murdering us! revenge! Hundreds of barricades were erected in a few hours, the arsenal was stormed, and a furious fight ensued, which raged till the morning of the next day, when the king commanded the retreat of the troops and their removal from the city. The corpses of the fallen combatants were carried into the courtyard of the palace, and the king was compelled to appear before them with uncovered head; the palace of his then very unpopular brother William, prince of Prussia, was declared national property. The ministry was dismissed, a civic guard organized, and a general amnesty granted. Mieroslawski, who had been sentenced to death, was carried in triumph through the streets of Berlin, and 250 of his associates left the prison with him, and hastened to Posen to commence the restoration of Poland, the new ministry promising its assistance. The king now openly and ostentatiously declared his purpose to take the lead in Germany; the diet was again assembled (April 2), to elaborate a new election law.

It was dissolved after the passage of that law on April 5, and a constituent assembly was convened in Berlin (May 22), while the delegates of Prussia also appeared in. the national German parliament which in Frankfort had superseded the diet of the princes (Bundestag). Prussian troops were sent to Schleswig-Holstein to assist the German inhabitants in their revolt against the king of Denmark. In Posen, however, where the Poles had risen in a bloody insurrection, the troops restored order after furious contests with the half-armed bands under Mieroslawski (April and May). This was the first reactionary victory. Others followed. While the revolution was losing its time in endless speech-making, framing of constitutions, and scheming on the reorganization of Germany as a united empire, in the assemblies of Frankfort, Berlin, Vienna, and elsewhere, the governments, which had maintained their armies, paved the way for a complete restoration of their power by mutual understanding, skilful counter-revolutionary manoeuvres, continually changing ministries, and varying programmes.

Emboldened by the fidelity of the army and the growing desire for order among the wealthier classes, by the reaction in France, and the successes of the Austrian government in Prague, Lom-bardy, and Vienna, Frederick William prorogued the Prussian constituent assembly, transferring it to the town of Brandenburg, closed its sessions by an armed force under Wrangel (November), and finally dissolved it shortly after its reassembling in Brandenburg (Dec. 5), promulgating a liberal constitution of his own. The new elections took place according to the king's constitution, and the two chambers were convened in Berlin (Feb. 26, 1849), which remained in a state of siege. Of these the lower house was still too revolutionary, and both were dissolved (April 27). In the mean time the king had not only abandoned the cause of Schleswig-Holstein by the armistice of Malmo, but had also declined the hereditary imperial crown of Germany offered him (March 28) by the Frankfort parliament. The Prussian army suppressed the revolution in Dresden, after a bloody struggle of three days (May), and in the Palatinate and Baden (June), while it was hardly more than a spectator in the renewed struggle in Schleswig-Holstein. A confederation of Prussia with Saxony and Hanover (Dreikonigsbund), and some minor northern states, formed March 2(3, was hailed by the so-called party of Gotha (Gagern, Dahl-mann, etc.) as the last hope for a union of Germany. It ended in failure.

Opposed by Austria and its southern allies, it was given up by Saxony, Hanover, and others; its parliament of Erfurt assembled in vain (March 20, 1850). Frederick William, who had convoked a new Prussian assembly and confirmed a new constitution with his royal oath (Feb. 6), followed for some time a more popular course in the affairs of Hesse-Cassel (October), but soon yielded to the threats of Austria and her allies (November). Order was restored in Hesse and in Schleswig-Holstein, and the ancient Germanic diet was once more established in Frankfort. The revolution was over. Chevalier Bunsen, who had lost his former liberal intfu-ence over the king, was obliged to sign the protocol of London in the Danish question (1852), which sealed Prussia's final surrender to the general reaction. Only Neufchatel remained with Switzerland as a conquest of the revolutionary movement, and after some threats of war in 1857 it was ceded to that republic. The policy of the government was peaceful, and Prussia took no part in the Crimean war, though it participated in the peace of Paris (1856). The constitution was modified and remodified; the revolutionary members of the assembly of 1848, Jacoby and others, were persecuted; the nobility (die Junker) and the pietists received new influence; the freedom of the press and of religion was circumscribed.

In 1857 the king was seized by a malady connected with temporary insanity, which compelled him (Oct. 23, 1858) to give up the personal management of affairs, and travel in Italy and the Tyrol for his health. His marriage with Elizabeth, princess of Bavaria, being without issue, his brother William (present emperor of Germany) became regent, and succeeded to the throne in January, 1861.