thumb|Kościuszko, aged 15, in 1761Kościuszko was born in February 1746 in a manor house on the Mereczowszczyzna estate near Kosów in Nowogródek Voivodeship, Grand Duchy of Lithuania, a part of the Polish–Lithuanian Commonwealth.Institute of World Politics, 2009, article. His exact birthdate is unknown; commonly cited are 4 FebruaryHerbst, 1969 p. 430. and 12 February.
