Interest in the power of heads of field offices in the United Nations Organization (UN) began with the researcher's appointment to such a position and with anecdotal suggestions that any explanation of the powers they held would be complex. For these reasons, this study has the research aim of explaining the power of some UN heads of field offices. The study focusses on seven heads of field offices in the United Nations Educational, Scientific and Cultural Organization (UNESCO). Literature searches indicated that no academic study had been made of any UN field work but the searches produced considerable literature on the UN and a wide range of theories about organizations, leadership and power, related issues of ethics and rationality and useful concepts from the work of Weber and Foucault. The research is interpretive. A case study and an appropriate conceptual framework were designed to reflect both the literature and the three research questions that promote the aim: organizational bureaucracy, organizational capital and frontline work are the guiding concepts. Because case studies may be challenged for possible lack of rigour and for validity, a number of data collection and analysis methods were used to promote reliability: both the data sources and the analysis checks included participants, UNESCO documents and information from other international bodies. Appropriate literature is also used for theoretical analysis. The results are presented progressively in three chapters, each chapter focussing on one framework concept and its appropriate question. The relevant data are presented and theoretical analysis, including selected concepts from Weber and Foucault, suggests answers to each question posed. The research results suggest that in the organization the participants gain power from UNESCO's intellectual and ethical purpose but are constrained in its use by processes of the bureaucracy, especially its lines of communication. The participants also have considerable power in organizational capital that includes tangible capital of qualifications, experience, skills, high level of position, the resources of the post in which they work and the intangible capital of the assumptions they hold about their work. At the frontline, although constrained by bureaucratic processes that limit their time for programme work, participants report valuable contributions to UNESCO's development and advocacy work: they gain power fiom proximity to the countries they serve and from their ethical motivation. They also gain some power in the freedom of distance from their headquarters, thus weakening the possible double jeopardy by being in a class-at-the-frontline and being in a group-not-in-headquarters. The final chapter brings all suggestions together and examines participants' power for sources (as rights or capacities), limitations (as control or domination) and agency (with compliance and resistance); when these perspectives are combined in a circle of power, the study suggests a Janus syndrome in which participants paradoxically are powerful/powerless agents, sited as they are between the power provision and constraints of both their bureaucracy and the governments and other bodies with whom they work.