This entry examines John R. P. French and Bertram Raven’s (The bases of social power. In: Cartwright D (ed) Studies in social power. Institute for Social Research, Ann Arbor, pp 150–167, 1959) original five bases of power used to determine a leader’s influence over subordinates. Specifically, these five influential bases were referent power, expert power, coercive power, reward power, and legitimate power. Dichotomized into two categories (i.e., formal and informal), each power may be applied according to a predetermined hierarchical organizational structure for formal powers (e.g., legitimate, reward, and coercive), or for informal powers, it may be earned based on one’s expertise and/or likability. For more than 70 years, scholars continue to research the impact these bases of power have on subordinates and others in similar roles. Each power influences subordinates in different manners, often with the intention to motivate. This entry includes an introduction to each of French and Raven’s power dynamics and their respective impact on leadership.