Here are the 16 most successful CEOs in Europe, according to the Harvard Business Review

Every year, the Harvard Business Review (HBR) releases a ranking of the world's best-performing CEOs.

The ranking is created by looking at four key variables, three related to the financial fortunes of the companies run by each CEO, and one relating to what the HBR calls "environmental, social, and governance".

ESG, as it is known, takes into account factors like how much hazardous waste a company produces, to how well it engages with society in the markets it operates in.

These four variables are then combined to give a score that helps identify how well a company is performing, and as a result how the big boss is doing.

Although American companies and bosses dominate the list - 41 CEOs featured in the top 100 lead companies headquartered in the United States - there were a number of CEOs who represent companies based in Europe, and the best CEO in the world is even based at a European firm.

Business Insider pulled out those names and ranked them, based on their spot in HBR's top 100, including the overall ranking of each CEO.

A previous version of this ranking included several CEOs who have now left their positions. They have been removed from this post.