Unsurprisingly, there are many people to acknowledge in a project like this. Top of the list is my Ph.D. thesis supervisor, Bruce Duncan, who recognised the potential of this research project from the outset and has unfailingly encouraged, advised, corrected and – to use a Cardijn term that Pope Francis has further popularised – ‘accompanied’ me from beginning to end.

Also vital to the project were those veterans of Vatican II, former YCW and other movement leaders, who knew Cardijn and kindly shared their recollections and experiences, including the late conciliar peritus, François Houtart, Chilean Council Father, Archbishop Bernardino Piñera, who was the world’s oldest living bishop at the time of his death in 2020, Australian John Maguire, who was ‘ecclesiastical assistant’ or chaplain to the lay auditors at the Council, Flo Triendl, Joseph Weber and Rienzie Rupasinghe, who worked with Cardijn. Michael Costigan, John Molony, Archbishop Len Faulkner, Richard Buchhorn, Don O’Brien, Bill and Anne Byrne, Bob Wilkinson, Michael Coleman, Nancy Conrad, Osvaldo Rebolledo, Mario Molina, Osvaldo Donoso kindly gave interviews which assisted greatly in understanding the background.

Also deserving of specific thanks are the archivists at the various institutions where I have worked. I would particularly like to mention Serge Sollogoub at the Institut Catholique de Paris, Frédéric Vienne at the Lille Diocesan Archives, and the ever-helpful staff at the Belgian Archives du Royaume in Brussels. Many others assisted by reading and/or commenting on drafts of various chapters and/or in various conversations. A few of those are Kevin Ahern, Dries Bosschaert, Oscar Cole-Arnal, Leo Declerck, Jean-Marie Dumortier, Guido Goossens, Joe Holland, Eric Mahieu, David Moloney, Val Noone, Bob Pennington, Oscar Saldarriaga, Antoine Sondag, Helen Ting, Stefaan Van Calster and special mention to Jean-Paul Durand, who first encouraged me to study the sources and origins of the JOC some twenty-five years ago. Thanks also to my thesis examiners, Mathijs Lamberigts and Ana-Maria Bidegain.

The Australian Research Theology Foundation provided a grant that enabled me to kickstart my research. Yarra Theological Union and the University of Divinity in Melbourne enabled me to obtain an Australian Government-funded PhD research scholarship. Special thanks to Michael Kelly and also to Suman Kashyap, who took care of many thankless administrative matters. Many others too numerous to mention also provided logistical and other assistance in large or small measure.

Naturally, I would also like to acknowledge the tremendous support and patience of Helen, my wife, whom I have already mentioned for her academic advice, my daughter Kiara, who assisted with checking various references, as well as Jade and Robbie, who also ‘accompanied’ me throughout this project.

The last and perhaps ultimate acknowledgement goes to the late Marguerite Fiévez, the de facto first secretary general of the JOC Internationale, later Cardijn’s personal secretary, archivist for Cardijn, the JOCI and the Belgian JOC as well as an historian and Catholic lay leader in her own right, who became a member of the original Pontifical Council of the Laity established after Vatican II.

Marguerite also compiled Cardijn’s first and only full-length book, Laïcs en premières lignes, which played a key role in transmitting the Jocist influence into the Council. She did untold behind the scenes work for Cardijn. Moreover, her networking skills also undoubtedly played a vital role in combination with Cardijn’s advocacy at the Council.

Stefan Gigacz