British University Observatories fills a gap in the historiography of British astronomy by offering the histories of these observatories identified as a group by their shared characteristics. The first full histories of the Oxford and Cambridge observatories are here central to an explanatory history of each of the six that undertook research before World War II - Oxford, Dunsink, Cambridge, Durham, Glasgow and London. Each struggled to evolve in the middle ground between the royal observatories and those of the 'Grand Amateurs' in the nineteenth century.<BR>Fundamental issues are how and why astronomy came into the universities, how research was reconciled with teaching, lack of endowment, and response to the challenge of astrophysics. One organizing theme is the central importance of the individual professor-directors in determining the fortunes of these observatories, the community of assistants, and their role in institutional politics sometimes of the murkiest kind, patronage networks and discipline shaping coteries. The use of many primary sources illustrates personal motivations and experience.