Russian Nobility, Diplomat. He was a Baltic German nobleman, who participated in the government of the Russian Empire. Born the son of Baron Andrei Romanovich Von Lieven and his wife Charlotte Karlova von Posse, he joined the Semenovskii Regiment in 1791 beginning his military career. He rose rapidly in rank, transferring to the Vladimir Dragoons then the Tula Rifle Regiment, serving in the Persian Campaign and in the Caucasus. He served during the Napoleonic campaigns, was a witness to the treaty of Tilsit, and became General-Lieutenant in 1807. In 1799 he was created Count in honor of his mother's loyal services to the Russian Imperial family. On February 24, 1800 he married the fifteen-year-old Dorothea Christoforovna Benkendorff, a lady-in-waiting of Russian Empress Maria Feodorovna. Later in his career, she was known for being a gracious hostess with a political sense. His wife's oldest brother, Count Alexander Benkendorf, was aide-de-camp to the Emperor Nicholas and later as Chief of the Secret Police, had the ear of the Tsar. By 1808, he had joined the Ministry of Foreign Affairs and was appointed Plenipotentiary Extraordinary to Berlin in 1809. He was at the Berlin Embassy from 1810 to 1812. After 1810, the political ties between England and Russia were delicate in relationship to the naval trade in the Baltic Sea. In 1812 he was appointed Ambassador to London, where he was well-respected in political and diplomatic circles during his twenty-two-year term. While he was Ambassador to London, his wife, though not especially beautiful or intelligent, was accepted into English society and credited with first introducing the Austrian waltz and the Christmas tree to the English. His wife was elected in 1814 as the first foreign patronesses of Almack's Assembly Rooms at King's Street in London, an upper-class mixed-sex public social venue. Nicknamed "Sibyl of European diplomacy", his wife's portrait hangs in the National Gallery in London, another by British court painter Sir Thomas Lawrence at the Tate Museum, and one at the Hermitage Museum in Russia. At the coronation of the Russian Emperor Nicholas in September of 1826, he received the title of Prince. He and his wife had a daughter, who died in infancy, and five sons, yet only two sons, Alexander and Paul, alone survived their parents. His sons Arthur and George died in St. Petersburg during a scarlet fever epidemic in 1835, while Constantine died in the United States in 1838. Even before the birth of their last son, his marriage was troubled, and the couple lived separate lives for periods starting in 1818. Many of his political colleagues as well as adversaries were smitten with his wife. Among his wife's closest confidants were Austrian Foreign Minister Klemens von Metternich; Prime Minister of the United Kingdom, Arthur Wellesley, 1st Duke of Wellington; George Canning, FRS; Prime Minister Henry John Temple, 3rd Viscount Palmerston; King George IV; Eugène François d'Arnauld; and Prime Minister of the United Kingdom, Sir Robert Peel, 2nd Baronet. Following notorious rumors that his wife, who was a devoted Russian subject, had become too involved, directly or indirectly, with highly classified matters concerning the British government, he was called back to St. Petersburg at the request of the British Prime Minister. His wife has been credited with playing a key role in the birth of modern Greece and made a notable contribution to the creation of Belgium during the 1830s. After returning to Russia in 1834, he was appointed to a post to accompany the Tsarevich, who later became Alexander II of Russia, to Stockholm, Copenhagen, Berlin and later toured southern Europe including Italy. After becoming part of British society, his wife stayed in England for a time before relocating to Germany, yet shortly after burying their sons, relocated to the warmer climate of Paris in 1835. He died very suddenly in 1838, while in Rome. Documenting his life's events, his wife wrote countless letters during his career as well as after his death. While in Paris, his widow became a close confidant of François Guizot, a high-ranking French politician, who shared the grief of a son's death. The couple exchanged over 5,000 letters in a close twenty-year friendship. His wife's 1827 letters, which were written in French, to Prince Paul Metternich, Chancellor of the Austrian Empire, were translated to English and published in 1937. His wife's correspondence with Prime Minister Earl Grey was published in 3 volumes in London in 1890, and her letters to twice Prime Minister Henry John Temple, 3rd Viscount Palmerston were published in 1943, which all give much insight in the Regency Era in England.