He persuaded Duke Christian August II of Schleswig-Holstein to renounce his claims to the duchies of Schleswig and Holstein and transfer them to the Danish crown.
[1] In the spring of 1854 he was appointed envoy in Saint Petersburg to lead the negotiations regarding the compromise between Austria and Russia as a result of the Crimean War.
A few weeks earlier, King Friedrich Wilhelm IV of Prussia temporarily entrusted him with the duties of Undersecretary of State in the Foreign Ministry.
Austria, in consultation with France and Great Britain (the Ottoman allies in the Crimean War), presented Russia with a four-point note as the basis for ultimate peace negotiations.
[1] In 1869, Werther replaced Robert Heinrich Ludwig von der Goltz as the Ambassador of the German Confederation in Paris during the Second French Empire under Napoleon III.
[1] In 1874, three years after his retirement, Bismarck briefly reactivated him by appointing him Ambassador of the German Empire in Constantinople to succeed Robert von Keudell because of Werther's experience with the Crimean War.
Like his father before him, he became an honorary knight of the Order of Saint John His written legacy, which dates from 1859 to 1870, is in the Prussian Privy State Archives in Berlin.
[1] Baron von Werther was married to Countess Mathilde Sophie Adelheid Lobo da Silveira von Oriola (1827–1889), a daughter of Joaquim Lobo da Silveira, 7th Count of Oriola (of the Portuguese nobility) and the former Sofia Murray (daughter of Dr. Johan Andreas Murray).