I SHOULD LIKE TO OFFER some words of thanks to the many people and institutions whose assistance made this book possible. First of all, I am grateful to the Center for Research on the History and Culture of Polish Jews at the Hebrew University of Jerusalem for supporting my endeavours in this field. I should also like to thank the Hanadiv Charitable Foundation of London (now the Rothschild Foundation Europe) as well as the Polish Committee of Scientific Research for their research grants; the YIVO Institute for Jewish Research, which supported my work in its initial stages through the Professor Bernard Choseed Memorial Fellowship; and the Dubnow Institute of Leipzig, which provided me with hospitality and support as I started preparing my typescript. I also received financial assistance from my alma mater, the Institute of Polish Philology at Wrocław University. I express my deepest gratitude to all these institutions, and even more to all those who represent them.

Further thanks are due to the institutions that allowed me access to their collections. Among them are the library of Wrocław University; the state archives in Częstochowa, Grodzisk Mazowiecki, Kalisz, Katowice, Kielce, Lublin, Łodź, Płock, Radom, Sandomierz, and Włocławek; theWarsaw Central Archives of Historical Records; the National Library and the Library of the University of Warsaw; the Jerusalem Central Archives for the History of the Jewish People; the National Library of Israel and the Library of the Hebrew University; and the library and archive of the YIVO Institute for Jewish Research in New York.

Among the many individuals to whom I am indebted I should mention Israel Bartal, without whose keen interest in my work and support this book would not have been written; Moshe Rosman, for recommending this book for publication and early advice; David Assaf, Gershon Bacon, Gershon Hundert, Marek Urbański, and Scott Ury for their many valuable critical remarks; Agnieszka Jagodzińska, who helped me find and acquire the illustrative material; and finally Andrzej Chwalba, Maciej Mycielski, and Shaul Stampfer, who agreed to read the typescript. I was further greatly helped by the weekly discussions of the research group Towards a New History of Hasidism, hosted in 2007–8 by the Institute of Advanced Studies at the Hebrew University of Jerusalem, of which I had the honour to be a fellow. Again I should like to thank cordially all those mentioned (and, with apologies, those not mentioned).