Each year, CEOs face new and different challenges in order to keep their companies running smoothly, particularly now during these uncertain volatile times that includes geopolitical issues, such as the Brexit vote, the Middle East, and the US election. So, what makes a CEO successful and how do some business leaders still manage to train their sights on the long term and deliver strong performance over many years? Well, the latest Harvard Business Review (HBR) 2016 list reveals the world’s top performers; these are the 100 best performing CEOs, based on both financial and Environment, Social and Governance (ESG) measures of the leaders’ entire time in office.