Prolific mathematician, born in France, who later settled in England. In De Moivre’s Theorem, he is remembered for his use of complex numbers in trigonometry. But he was also the author of two notable early works on probability. His Doctrine of Chances of 1718, examines numerous problems and develops a number of principles, such as the notion of independent events and the product law. The later work contains the result known as Stirling’s formula and probably the first use of the normal frequency curve.