Servant leadership focuses on serving followers and helping them grow. It originated from Robert Greenleaf who said the test of servant leadership is whether those being served become healthier, wiser and more likely to become servants themselves. Servant leadership engages followers spiritually and transforms and ethics the leader. It defines the best leader as a servant to subordinates. Principles include encouraging diversity, creating trust, having an unselfish mindset, and fostering leadership in others. Advantages include high morale, collaboration, ethical behavior and contribution from all, while disadvantages include taking time to build and not working for every organization.