In February 1782, during the
American War of Independence,
Admiral Sir George Rodney sailed again for the
West Indies after a period of leave, and Thesiger gained a commission as acting-lieutenant on board
HMS Formidable. He caught the eye of
Admiral Sir Charles Douglas, captain of the fleet, and on his recommendation he was appointed as
flag lieutenant to Rodney on the eve of the last day of the
Battle of the Saintes. In 1789, Thesiger was given command of a 74-gun warship. In a naval engagement on 25 August, the Swedish admiral on board a ship called
Gustavus surrendered to Thesiger. In June 1790, Thesiger was one of six English captains who fought in an action off the island of
Bornholm, and the only one of the six not killed.
Catherine the Great gave Thesiger the
Order of St. George. He stayed in her service after the war ended in 1790. From 1792, Great Britain and Russia were allies in the
French Revolutionary and Napoleonic Wars, and in 1796 Thesiger was with a Russian squadron which came to the North Sea to work with the Royal Navy in the blockade of the
Texel. After Catherine the Great died in 1797, Thesiger found her successor,
Paul, less easy to work for and resigned. He was kept in St. Petersburg for a year and at last left without his arrears of pay or his
prize money, and returned to England. There, he was useful to
George Spencer, 2nd Earl Spencer, at the time
First Lord of the Admiralty, thanks to his knowledge of the Baltic and the Russian navy. The
War of the Second Coalition broke out in November 1798, and Thesiger was commissioned into the Royal Navy as a Commander. At the
Battle of Copenhagen (1801) he was Nelson's aide-de-camp. In later operations in the Baltic his knowledge of the coast was valuable to the British. Returning to England with despatches from
Sir Charles Morice Pole, he was well received by
St Vincent, promoted to
post-captain, and given permission to wear the Russian Order of St George and to call himself Sir Frederick. On the
breakdown of the
Treaty of Amiens in 1803, the
Napoleonic Wars began, and Thesiger was appointed as British agent for prisoners of war at
Portsmouth. He died, still unmarried, at Elson, near Portsmouth, on 26 August 1805. ==Notes==