The author describes the fundamentals of the audit committee as a committee of the board of directors of a public company. Based on the global convergence of governance and control systems, corporate governance codes are identified as key drivers for the establishment and design of audit committees. The theoretical explanatory models of principal-agent theory and stewardship theory are presented and weighed against each other. To understand the proliferation of audit committees, milestones worldwide are described chronologically, and then the relevant regulations in Switzerland are identified along with their requirements for the design of an audit committee.