He studied atBerlin, in 1839 becoming a lecturer there, and in 1845 professor. In 1851, he became professor for history at theUniversity of Zürich; nine years, he went to theUniversity of Jena, where he remained for the rest of his life. He was a member of theFrankfurt Parliament in 1848, and of the GermanReichstag from 1874 to 1876.
This is his main body of work, mostly limited to the 19th century. The most important are:
Geschichte der Denk- und Glaubensfreiheit im ersten Jahrhundert der Kaiserherrschaft und des Christentums (1847)
Preussens deutsche Politik (Berlin, 1850, and other editions)
Geschichte der preussisch-deutschen Unionsbestrebungen (Berlin, 1851)
Zeitgenössische Geschichten: I. Frankreich von 1815 bis 1830. II. Oesterreich von 1830 bis 1848 (Berlin, 1859)
Elsass und Lothringen (Leipzig, 1859 and 1870)
Geschichte der deutschen Verfassungsfrage während der Befreiungskriege und des Wiener Kongresses (Stuttgart, 1890), which was published after his death by A Stern.
He edited the 8th issue ofKarl Friedrich Becker'sWeltgeschichte, 22 vols. (Leipzig, 1874–79).