This thesis investigates the process of reforming the rule relating to celibacy for Fellows of Oxford and Cambridge colleges. This is the first full length study of the changes in Statutes removing the ban on marriage for Fellows of university colleges, combining research into university, religious, legal and social history. This study traces the origins of the obligatory rule of chastity at the universities' foundations until revision of their Statutes in 1882. Originally students at the universities undertook training as priests even if destined for other professions, therefore chastity was obligatory. The roles of the Church, Crown, and Parliament have been studied in relation to the origins of celibacy for priests, its continuance at the university colleges, throughout the reformation of religion, its preservation until almost the end of the nineteenth century and the consequences of intervention from all three establishments. The main structure of college administration, staff, way of life, and the impact upon reform of events, arguments and debates on the advantages and disadvantages of the system have also been examined and assessed.