Based upon perspectives and concepts from social and historical research on technical systems, this dissertation describes and analyses events and processes relating to the dramatic change in television in Western Europe during the 1980s and early 1990s. In particular, it focuses on how Swedish television, conceived as a large socio-tecnical system, has shifted from a traditional 'public service' system to a more open and mixed system. In addition to traditional public television broadcasting, it has now come to encompass several commercial channels distributed through an expanding combination of technical and market alternatives, including satellite television. The study traces the multiple ways in which socio-historical processes and contingencies have shaped the television system in Sweden. The most detailed historical descriptions and analyses focus on the entrepreneurial activities of the Swedish firm, Industriförvaltning AB Kinnevik, documenting the introduction of the satellite channel TV3 in Sweden and the related expansion of the system. The entrepreneurial actions of Kinnevik in establishing the new satellite channel TV3 are analysed against the background of (1) the characteristics of the traditional Swedish radio and TV broadcasting system, (2) the development of cable television in Sweden, and (3) the broad history of satellite television. Emphasis is placed on how and why it was possible for a new actor to successfully challenge, gain access to, and help transform a well-established system that had remained relatively stable for a long time. This raises attendant questions of timing. How do we account for and explain the relative stability of this system for such a long period? Why did radical change occur at a particular time and not before or after? Whereas the empirical material concerning the activities of Kinnevik in relation to its entrance on the television market covers the period between 1984 and 1991, the study in general addresses developments throughout the twentieth century and, occasionally, even further back in history. The focus is thus on the system as a whole, rather than on only one of its components. A number of conclusions are drawn from the study concerning both the construction of new systems and the reconstruction of established systems. Two major conclusions can be mentioned here. (1) First, the historical material confirms the necessity of collective action in large-scale technology-based entrepreneurial action. (2) Second, the study also shows that there is nothing necessary or inevitable about the development of technologies/technological systems, even though they are subject to a high degree of path-dependence. / <p>The electronic version of the printed dissertation is a corrected version where all spelling and grammatical errors are corrected.</p>