Yet another source states that he was born Sigmund Georgievich Rosenblum on 24 March 1874, the only son of Pauline and Gregory Rosenblum, a wealthy Polish-Jewish family with an estate at Bielsk in the Grodno Province of Imperial Russia. His father was known locally as George rather than Gregory, hence Sigmund's patronymic Georgievich. The family seems to have been well-connected in Polish nationalist circles through Pauline's intimate friendship with Ignacy Jan Paderewski, the Polish statesman who became Prime Minister of Poland and also Poland's foreign minister in 1919.