He was born in Copenhagen, son of Martin Christian Gottlieb Lehmann (1775–1856), assessor, later conference councillor (konferensraad) and deputee in the College of Commerce. The father was German, born in Haselau at Uetersen in Holstein, while the mother was Danish and daughter of a Mayor in Copenhagen. The family belonged to the same social circle as the Ørsted brothers and the poet Oehlenschläger. Orla was put in the German realschule in the St. Petri parish, later moved to the Borgerdydskole and began his studies at the University of Copenhagen in 1827. After a year studying literature, when he read Heine in the company of H. C. Andersen, he began his Law studies. After a study programme which he found tedious, he graduated in 1833.
Although of German extraction, Orla Lehmann's sympathies were with the Danish National Liberal Party. and he contributed to the liberal journal the Kjøbenhavnsposten while he was a student, and from 1839 to 1842 edited, with Christian N. David, the Fædrelandet. In 1842 he was condemned to three months imprisonment for a radical speech. He took a considerable part in the demonstrations of 1848, and was regarded as the leader of the Eider-Danes, that is, of the party which regarded the Eider River as the boundary of Denmark, and the Duchy of Schleswig as an integral part of the kingdom.
He entered the Cabinet of Moltke I in March 1848, and was employed on diplomatic missions to London and Berlin in connection with the Schleswig-Holstein Question but left the cabinet the same year because of his dissatisfaction with the political situation. As a local official in Jutland he was for some months in 1849 a prisoner of the Schleswig-Holsteiners at Gottorp. A member of the Folketing from 1851 to 1853, of the Landsting from 1854 to 1870, and from 1856 to 1866 of the Rigsråd, he became Minister of the Interior in 1861 in the cabinet of K. C. Hall, retiring with him in 1863.
During these years he was overshadowed by the younger National Liberals especially by Hall, however he in many ways did a great work behind the scenes, for instance it was he who carried through the law of women’s economic independence. His last years were embittered by the defeat of 1864 and by his presentiment of the new German great power. He died in Copenhagen in September 1870.
Being one of the most stirring speakers of early Danish parliamentarian life (almost like Lamartine in France) and besides a charming and committed man Lehmann however seems to have lacked both sense of reality and a more heartfelt sense of democracy. As “the freedom fighter of 1848” he remained a national hero in Denmark for several generations but he was not able to maintain his influence.
His book On the Causes of the Misfortunes of Denmark (1864) went through many editions, and his works were published posthumously in four volumes.
| Minister without Portfolio of Denmark
22 March 1848 – 15 November 1848
Henrik Nicolai Clausen
Ditlev Gothard Monrad
| Interior Minister of Denmark
15 September 1861 – 31 December 1863
Carl Ludvig Vilhelm Rømer von Nutzhorn
- Orla Lehmann: Orla Lehmanns efterladte Skrifter. 4 bd. Kjøbenhavn, 1872-1874
- Orla Lehmann: Af Orla Lehmanns Papirer: Bidrag til Danmarks Tidshistorie i det 19. Aarhundrede; udg. af Julius Clausen. Kjøbenhavn, 1903
- Orla Lehmann: Om Aarsagerne til Danmarks Ulykke: et historisk Tilbageblik. Kjøbenhavn, 1864 (On the causes of the misfortunes of Denmark)
- C. E. F. Reinhardt: Orla Lehmann og hans Samtid: et Bidrag til Belysning af Friheds- og Nationalitets-Tankens Udvikling i Danmark. Kjøbenhavn, 1871
- Johannes Jensen, 'Martin und Orla Lehmann. Die Integration einer deutsch-dänischen Sankt-Petri-Familie,' in Sankt Petri Kopenhagen 1575-2000. 425 Jahre Geschichte deutsch-dänischer Begegnung in Biographien, ed. Jürgen Beyer & Johannes Jensen (Copenhagen: C. A. Reitzel, 2000), pp. 113–131
This article incorporates text from a publication now in the public domain: Chisholm, Hugh, ed. (1911). "Lehmann, Peter Martin Orla". Encyclopædia Britannica. 16 (11th ed.). Cambridge University Press. p. 384.