In that year he met Alexander Suvorov, and took up his recommendation to join the Imperial Russian Army as a Lieutenant General and chief of the Riga Cuirassier Regiment which in August 1800 was reorganised into Riga Dragoon Regiment while Alexander was promoted to General of Cavalry (the rank below Field Marshal).

[1] During the 1812 Campaign Württemberg served at the Headquarters of the 1st Western Army and fought at Vitebsk, Smolensk, Borodino, Tarutino (awarded Order of St. George, 3rd class), Maloyaroslavets, Vyazma and Krasnoi.

[1] In 1813 he commanded the Siege of Danzig for which he was awarded a golden sword and the Order of St. George (2nd class).

In 1822 he became the Head of the Communications Department (responsible for transport links) and initiated several large-scale waterway projects (the Windawski Canal, etc.)

[1][2] In 1826 Württemberg was appointed chief of Ekaterinoslav Cuirassier Regiment, and a member of the State Council, but returned to the Riga Dragoons in 1827.