As our world has become increasingly complex, everything has changed; yet, in an even larger sense, nothing about great leadership has changed. Just as the great institutions of the past had strong but different cultures underpinned by explicitly stated or implicitly understood values and principles, so too, the great organizations of today and tomorrow require top leaders who consider their most important job to be the creation, nurturing and, yes, carefully adapting value-based cultures which enable organizations and their people to prosper while consistently adhering to well-understood values and operating principles.