All of the people listed have one thing in common - they were leaders. Leadership is defined as influencing others to achieve goals through change. It is difficult to define but involves influencing groups to achieve common goals. Leadership requires competencies in self-management, leading people, and managing tasks. Effective leaders are also effective communicators, using communication to motivate and influence others. Followership is also important to leadership - one cannot be a great leader without great followers, and followers are active participants in the leadership process.