Marie Sophie Gräfin von Brühl (Countess Marie Sophie von Brühl; 3 June 1779 - 28 January 1836) was a member of the German von Brühl noble family originating in Thuringia

Thuringia

The Free State of Thuringia is a state of Germany, located in the central part of the country.It has an area of and 2.29 million inhabitants, making it the sixth smallest by area and the fifth smallest by population of Germany's sixteen states....

.

She was born in Warsaw

Warsaw

Warsaw is the capital and largest city of Poland. It is located on the Vistula River, roughly from the Baltic Sea and from the Carpathian Mountains. Its population in 2010 was estimated at 1,716,855 residents with a greater metropolitan area of 2,631,902 residents, making Warsaw the 10th most...

. On 17 December 1810 she married Carl von Clausewitz

Carl von Clausewitz

Carl Philipp Gottfried von Clausewitz was a Prussian soldier and German military theorist who stressed the moral and political aspects of war...

, whom she first met in 1803. She published several of his books in the years 1832-34 after his death in 1831, including his most famous one, On War

On War

Vom Kriege is a book on war and military strategy by Prussian general Carl von Clausewitz , written mostly after the Napoleonic wars, between 1816 and 1830, and published posthumously by his wife in 1832. It has been translated into English several times as On War...

. Additionally, von Brühl wrote a preface to On War.