The thesis examines the education of Catholic youths in penal times and links their education with the activities of the missionary priests and the recusant parents, who found means of primary education in the humanities before sending their sons abroad to be educated. The possibility of a clandestine school in Dalton-le-Dale in 1641 is considered, and an account is given of the attempts at organised education in Durham and Gateshead during the reign of James II. Source material is used to show where Catholic teachers practised in the eighteenth century and how schools were often linked with the foundations of missions. Support by the Catholic gentry for private education for rich and poor is examined, and there is a comprehensive account of the foundation at Tudhoe, its system of education, its links with Crook and Ushaw and its subsequent history as a Poor Law school. Education at Crook and Ushaw is treated as an integral part of the development of Catholic education in the county. Family papers are used to describe the education abroad in the late eighteenth century of a young Catholic gentleman (W. T. Salvin), and this account can be compared with the education of his own children in the early nineteenth century in a chapter that deals with private foundations at Stockton-on-Tees and Darlington. A major part of the thesis is concerned with the growth of the Catholic poor schools of the nineteenth century and their connections with the early missions. Original sources are used to trace the development of all the Catholic schools in the county and to compare their growth with national progress. It has been possible to give detailed accounts of all the Catholic poor schools in Durham, to chart their progress, examine their means of support and their qualification for grant, and to describe the way the Catholic teachers became qualified