He studied at the Department of Law of the Russian University of Warsaw and in Berlin and Leipzig. Until 1907 he was active in the Polish national movement. During the First World War he was connected with the political camp advocating the policy of Poland’s active support for the Central Powers – first as an émigré publicist in Switzerland, and then as a politician. From March 1917 to February 1918 he served as the Prime Minister of the Polish Kingdom appointed by the Regency Council. He is the author of the fundamental work about the origin of the Bolshevik revolution entitled Od białego caratu do czerwonego and published in seven volumes in 1922-1935. During the German occupation, he managed to escape from Poland and settled down in the United States. Kucharzewski was among the founders of the Polish Institute of Arts and Sciences of America headquartered in New York. He died in New York on the 3rd of July, 1952.