Aon
Founders
Patrick G. Ryan, W. Clement Stone · Founded 1982 · HQ today: Dublin, Ireland
Aon was founded by Patrick G. Ryan, W. Clement Stone in 1982 in Chicago, Illinois, United States. It is now led by Greg Case.
The story of Aon is the confluence of two iconic 20th-century American insurance entrepreneurs: W. Clement Stone and Patrick G. Ryan. In 1919, 16-year-old W. Clement Stone founded the Combined Registry Company in Chicago with just $100 in savings, selling low-cost accident and health policies door-to-door using his famous 'Positive Mental Attitude' (PMA) philosophy. Over six decades, Combined grew into a national direct-sales insurance power. Meanwhile, in 1964, 26-year-old Patrick Ryan founded Pat Ryan & Associates in Chicago, pioneering automobile dealership finance and insurance (F&I) programs. In August 1982, Ryan engineered a historic $500 million merger between Ryan Insurance Group and Combined International, taking leadership as CEO. In 1987, Ryan rebranded the merged enterprise as Aon—the Gaelic word for 'one'—symbolizing the unification of risk and people consulting. Ryan executed an aggressive international M&A strategy, acquiring Dutch broker Hudig-Langeveldt in 1991, Britain's Bain Clarkson in 1994, and Alexander & Alexander in 1997 for $1.23 billion, surpassing Marsh to become the world's largest broker. In 2005, former McKinsey partner Greg Case was appointed CEO. Case instituted the 'Aon United' operational framework, acquired reinsurance broker Benfield Group for $1.75B in 2008, human resources titan Hewitt Associates for $4.9B in 2010, and middle-market champion NFP for $13.0B in 2024, cementing Aon's place as a global professional services titan.
| Founder | Role at founding | Contribution |
|---|---|---|
| Patrick G. Ryan | Co-Founder and Former Chairman & CEO | — |
| W. Clement Stone | Co-Founder and Direct Sales Pioneer | — |
Patrick George Ryan (born 1937) is an American billionaire businessman and insurance visionary who founded Pat Ryan & Associates in 1964 and created Aon in 1982, serving as CEO until 2005. Ryan is an icon of the insurance industry and founder of Ryan Specialty Group.
William Clement Stone (1902–2002) was an American businessman, author, and philanthropist who founded Combined Insurance Company in 1919 with $100. Stone was world-renowned for his Positive Mental Attitude (PMA) philosophy and bestselling personal growth books.
Greg Case
Chief Executive Officer
Christa Davies
Former Chief Financial Officer & Senior Advisor
Edmund Reese
Chief Financial Officer
Eric Andersen
President, Aon plc
Mindy Simon
Chief Operating Officer
Aon was established through the visionary leadership of Patrick G. Ryan, who built Ryan Insurance Group, and W. Clement Stone, who founded Combined Insurance Company of America. The two corporate insurance innovators merged their respective companies in 1982 to create Aon.
Patrick G. Ryan began his entrepreneurial career in 1964 by creating finance and insurance products sold directly through automobile dealerships. His aggressive acquisition strategy throughout the 1970s and 1980s transformed a localized agency into an international commercial brokerage titan.
W. Clement Stone founded Combined Registry Co. in 1919 with just $100 in savings, expanding it into Combined Insurance Company of America. A famous advocate of 'Positive Mental Attitude' philosophy, Stone's substantial insurance underwriting capital provided the springboard for Aon's 1982 merger.
W. Clement Stone built Combined Insurance from $100 using his 'PMA' (Positive Mental Attitude) sales methodology, authoring 'Success Through a Positive Mental Attitude' with Napoleon Hill and donating over $275 million to charity.
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