Friedrich August von Hayek (8 May 1899 – 23 March 1992) is rivaled by only Adam Smith as the preeminent theorist of the market system. Hayek's account of how changing relative prices communicate signals which enable individuals to coordinate their unique plans in an ever changing world is widely regarded as one of the landmark achievements of economic science. This and a host of other important contributions has made Hayek one of the most influential economists of modern times. One of the great polymaths of the 20th century, Hayek also made significant contributions in jurisprudence, neuroscience, philosophy and the history of ideas.
In 1974 Hayek shared the Nobel Memorial Prize in Economics with Gunnar Myrdal "for their pioneering work in the theory of money and economic fluctuations and for their penetrating analysis of the interdependence of economic, social and institutional phenomena." He also received the U.S. Presidential Medal of Freedom in 1991.
Hayek lived in Austria, Great Britain, the United States and Germany, and became a British subject in 1938.
In 1984, he was appointed as a member of the Order of the Companions of Honour (CH) by Queen Elizabeth II of the United Kingdom on the advice of the British Prime Minister Margaret Thatcher for his "services to the study of economics". After his twenty-minute audience with the Queen, he was "absolutely besotted" with her according to his daughter-in-law, Esca Hayek. Hayek said a year later that he was "amazed by her. That ease and skill, as if she'd known me all my life". The audience with the Queen was followed by a dinner with family and friends at the Institute of Economic Affairs. When, later that evening, Hayek was dropped off at the Reform Club, he commented: "I've just had the happiest day of my life".