One of the little known areas relating to education in Ireland is the area of young offenders who are held in detention schools as a result of a criminal conviction. The rationale for this research is to bring focus onto a closed system of education, thereby giving representation to a marginalised sector of educationally disadvantaged children in Ireland. The issues that arise from the intersecting systems of criminalisation and of education are explored and discussed in terms o f inequality, education, and confinement and with reference to the international experience o f best practice. The theoretical framework for this thesis draws upon the theories of Michel Foucault and Pierre Bourdieu, particularly in relation to power, discipline, capitals and habitus. Their theorisation of these concepts provide useful lenses through which to examine the history of detention and schooling, the educational processes involved in detention schools, the educational experiences and the classed identities of the children incarcerated in them. Using mixed methods, which include classroom observations and semi-structured interviews, the research takes a phenomenological approach, giving voice to the boys who are held in detention schools. It examines how the educational process in a detention school operates in terms of curriculum, teaching methodologies and forms of assessment, to establish the ways in which the educational engagement of boys in detention schools shapes their future outlooks and life chances. Tensions between criminalisation o f young people, confinement, education rights and provision are made explicit. The phenomenon that most of the children in detention come from communities that are socio-economically under-resourced is explored. The findings reveal that the children in detention schools had low levels of educational engagement prior to detention mainly due to absenteeism and failing to make the transition from primary to second-level school. They shared low socio-economic backgrounds, showed a capacity to reflect on their educational experiences and faced uncertain futures due to stigmatisation and labelling as criminals. Conclusions are drawn that show that due to small class numbers and intense classroom work with teachers the boys do make educational progress while in the detention schools. Teachers were found to be dedicated and aware of the needs of the children but somewhat stymied by lack of ongoing professional development and tensions with care staff in respect of the differences and sometimes crossovers between care and teaching. In conclusion it is proposed that a radically different approach both to confining and to educating children within the criminal justice system is taken.