Frederick William IV of Prussia

King Frederick William IV of Prussia (1795-1840), was the eldest son and successor of Frederick William III of Prussia. He reigned from 1840 to 1861. During the Revolutions of 1848[?], he was offered the Imperial Crown of Germany by the Frankfurt Congress[?], but turned it down, purportedly saying that he would not accept a crown from the gutter. In the following years, he became more and more mentally unstable, until in 1858 his brother, Prince William was made Regent. Frederick William died in 1861 and, being childless, was succeeded by his brother.