Academic interest in migrant history in Western Europe first developed in the 1970s within the expanding fields of social and labour history. Challenging the established ways of historiography that focused on the reconstruction of political events and ideas, the new social history was interested in social structures and processes, such as urbanisation and industrialisation, inequality and class conflict, mobility and social change. It put in the limelight those social groups that traditional history writing had overlooked, above all workers, women, immigrants and ethnic minorities. Consequently, class, gender and ethnicity became central categories of historical analysis. Initiated by pioneer scholars such as Colin Holmes in Britain, Klaus Jurgen Bade in West Germany, Gerard Noiriel in France, Harald Runblom in Sweden and Jan Lucassen in the Netherlands, migration history as a field of research emerged in the 1970s and 1980s. It created informal networks of historians, meeting at conferences and contributing to new journals such as Immigrant and Minorities.