Political sociology seeks to explore and explain the relationship between social and political phenomena and to place politics within its societal context. Many writers on politics have argued that power is its key concept, but it was Max Weber who focused particular attention on the exercise of power in the form of authority and thus on the concept of legitimacy. Studies of political socialisation, participation, and recruitment have grown in number and scope, and a more rounded picture of political behaviour within its social context is emerging. The dramatic and far-reaching changes in Eastern Europe and the Soviet Union arguably present political sociology with its greatest challenge. Public opinion and ideology have also received relatively little attention from political sociologists, although the literature on both is extensive and draws upon a wide variety of disciplines. If communication has been widely neglected in political sociology, societal change has been far from ignored.