Princess Darya Christoforovna Lieven, known as the "society lioness" of the first half of the 19th century, was a secret agent of the Russian government in London and Paris and earned the nickname "diplomatic Sibyl." She entered history as the first Russian woman diplomat. Darya received an excellent education for her time and married diplomat Christofor Andreyevich Lieven. In 1809, when her husband was sent to Berlin, she followed him.

In Prussia, Darya Christoforovna experienced boredom. In one of her letters, she wrote that pretending to be foolish for a few more years would be cruel. When her husband was sent to London three years later, she was very pleased. Following the fashion of the time, she opened a salon in the capital, which soon became frequented by all members of high society. By interacting with guests and engaging in social conversations, the princess gathered useful information. Memoirist Philip Wigel noted that Darya Christoforovna was much more astute than her husband and that she wrote the dispatches he sent to Russia. Over time, her influence on the political stage surpassed that of Count Lieven.

In 1815, Alexander I formed an alliance with Prussia and Austria, hoping that after the Napoleonic Wars, Russia would play a leading role in Europe. However, Austrian Chancellor Clemens von Metternich had his own plans. Attempts to bribe him were unsuccessful, and during the Congress of Vienna, he "accidentally" met Darya Lieven. She was tasked with winning his trust.

In her 45 years of espionage, the princess made no mistakes, and the Russian government always valued her opinions and information. As the Crimean War approached, Darya Lieven constantly sent warnings to the capital about the impending danger, but Nicholas I, unlike his predecessor, ignored them, considering them mere women's gossip. As a result, the Crimean War became an unexpected blow for Russia and ended in disgraceful defeat. Until the end of her days, Princess Darya Christoforovna Lieven remained devoted to her homeland.