Aon plc is an international professional services firm. It has two divisions: Risk Capital, which provides brokerage and consulting services for risk management, insurance and reinsurance, and Human Capital, which provides services related to health insurance, retirement plans, pension plans, and talent advisory. It is the second-largest insurance broker in the world and is ranked 300th on the Fortune 500 and 388th on the Forbes Global 2000. Founded in Chicago by Patrick Ryan, Aon was created in 1982 when the Ryan Insurance Group merged with the Combined Insurance Company of America under W. Clement Stone. In 1987, the holding company was renamed Aon, derived from aon, a Gaelic word meaning "one". The company's corporate headquarters is based in Dublin, while its global operations are based in London. It also maintains a major North American operational presence at the Aon Center in Chicago.