He and his elder brother Henri Lehmann studied in Paris at the École des Beaux-arts, in Rome, and with the painters Peter von Cornelius and Wilhelm von Kaulbach.
Wilhelm August Rudolf Lehmann (19 August 1819, near Hamburg – 27 October 1905, in Bushey) was a German-English portraitist and author He moved to the United Kingdom in 1866. Lehmann"s major painting, The Blessing of the Pontine Marshes by Sixtus V was shown in Paris in 1846 and bought by the French government.
In 1866 Lehmann settled in London, became a British citizen, and painted his best known portraits.
Amelia"s sister Nina married Lehmann"s younger brother Frederick, and the extended social circle of the two couples included Charles Dickens, George Eliot, Robert Browning, Lord Leighton, and other prominent figures. In 1896, a number of his engraved portraits were collected and published as Men and Women of the Century.
On 27 October 1905, he died at Boumemede, Bushey. He was buried in Highgate cemetery.
One of Lehmann"s daughters was Liza Lehmann, who became a notable English soprano and composer.
Lehmann was the uncle of the British journalist and politician Rudolf Chambers Lehmann.