This paper provides an analysis of changing patterns of transition from before the second world to the end of the twentieth century. It examines the longer term changes in the occupational structure and the consequential transformation of the patterns of labour market entry for young people. It links labour market entry to subsequent early work-life occupational mobility, arguing that this longer term perspective is essential in arriving at a fuller understanding of transitions. Two main changes are identified: a shift in labour market entry from manual to non-manual work, and from low- to higher-skilled jobs. Early life mobility increased up to the 1980s but then became more constrained in the later part of the twentieth century. The early labour market experience of young people remained heavily conditioned by class and gender throughout. An easing of gender disadvantage in the later periods being counterbalanced by an intensification of class disadvantage among both young men and young women. The combined impact of changes in the occupational structure and the associated patterns of entry to work and subsequent early work-life mobility is creating a pattern of disadvantage in the low-skilled sectors of the labour market. This is associated with persisting patterns of social exclusion among some groups of young people. Transitions research now needs to refocus on the continuing impact of both class and gender on the labour market experience of young people, extended over the early years of working life. This better connects transitions research to wider sociological analysis and to current policy concerns, potentially enhancing the contribution it can make to both. (Contains 2 figures, 6 tables and 3 notes.)