Jan Lucassen (PhD Utrecht University, 1990) is Emeritus Professor of Social History of the Free University in Amsterdam and as research fellow attached to the International Institute of Social History. His research focusses on labour migration and the history of work. Leo Lucassen (PhD Leiden University, 1990) is Professor of Social and Economic History at the Institute for History of Leiden University.
His work concentrates on global migration history, urban studies and the history of social engineering.