Jean-Marie Messier is a French businessman best known for his role as the CEO of Vivendi, a global media and telecommunications company. He led the company during a period of aggressive expansion in the late 1990s and early 2000s, acquiring various assets in the entertainment and telecommunications sectors. Under Messier's leadership, Vivendi faced significant challenges, including financial difficulties that led to his resignation in 2002. His tenure is often discussed in the context of corporate governance and the risks associated with rapid growth and diversification in the business world.