This work is the first systematic study of the presidency of the European Commission. Drawing upon cases of attempted leadership by Jacques Delors, the Commission President from 1985-95, it examines the leadership capacity of the office-holder. This points to the inherently shared and contingent nature of Commission President's leadership in a Union where the leadership sources are widely dispersed. While this is essentially an empirical study, Endo addresses some of the theoretical implications of its findings and resulting issues.