Frederick William IV, 1795–1861, king of Prussia (1840–61), son and successor of Frederick William III. A romanticist and a mystic, he conceived vague schemes of reform based on a revival of the medieval structure, with the rule of estates and a patriarchal monarchy. During the revolution of 1848 in Prussia, which broke out in March, Frederick William was forced at first to accede to revolutionary demands. Later, however, he crushed the opposition, dissolved (Dec., 1848) the constituent assembly, and promulgated a conservative constitution, which, as modified in 1850, remained in force until 1918. Frederick William refused the crown of a united Germany offered him (1849) by the Frankfurt Parliament Frankfurt Parliament, 1848–49, national assembly convened at Frankfurt on May 18, 1848, as a result of the liberal revolution that swept the German states early in 1848. The parliament was called by a preliminary assembly of German liberals in Mar.
..... Click the link for more information. on the grounds that a monarch by divine right could not receive authority from an elected assembly. Although unwilling to accept the crown from an elected assembly, Frederick William desired German unity under Prussian leadership and presented the Prussian Union plan for a confederation of Prussia and the smaller German states. Austrian opposition to the plan forced Frederick William to abandon it in the Treaty of Olmütz (1850). In 1848, Frederick William briefly supported the revolt in Schleswig-Holstein Schleswig-Holstein (shlĕs`vĭkh-hôl`shtīn), state (1994 pop. 2,595,000), c.6,050 sq mi (15,670 sq km), NW Germany.
..... Click the link for more information. against Denmark but yielded to British pressure for an armistice. In 1857 his mental condition necessitated a temporary (later permanent) regency of his brother, who succeeded him as William I.

Frederick William IV

German Friedrich Wilhelm

(born Oct. 15, 1795, Cölln, near Berlin, Prussia—died Jan. 2, 1861, Potsdam) King of Prussia (1840–61). The son of Frederick William III, he was a disciple of the German Romantic movement and an artistic dilettante, but his conservative policies helped spark the Revolutions of 1848, in opposition. In 1849 he refused the imperial crown offered by the Frankfurt National Assembly. His subsequent efforts to create a German union under Prussian leadership were thwarted by Austria (see Punctation of Olmütz). A stroke left him paralyzed in 1857, and his brother, the future William I, became regent in 1858.

1795--1861, king of Prussia (1840--61). He submitted to the 1848 Revolution but refused the imperial crown offered by the Frankfurt Parliament (1849). In 1857 he became insane and his brother, William I, became regent (1858--61)