VITAE was a four-year research project designed to explore the work and lives of a purposive sample of 300 Key Stage 1, 2 and 3 (English and maths) teachers at different phases of their careers in 100 primary and secondary schools in different socioeconomic contexts, drawn from seven local authorities in England. Its focus was upon identifying variations in different aspects of teachers' lives and work and examining possible connections between these and their effects on pupils as perceived by the teachers themselves and as measured by value-added national test scores. An integrated mixed-method approach was developed in addressing the research questions. The results showed that there were associations between teachers' work, lives and identities, that teachers' perceived and relative (valueadded) effectiveness varied within each of six professional life phases, and that this variation depended upon their capacity to manage a number of moderating and mediating factors. Statistically significant relationships were found between teacher commitment, resilience and the value-added pupil test scores. The findings from the study shed new light upon the meanings and measurement of teacher effectiveness and the complex nature and trajectories of teachers' work, lives and effectiveness in different school contexts.