Probability
Who was the first person to discover probability?
That would probably be Blaise Pascal in collaboration with Pierre de Fermat. You can find some interesting information regarding these two athttp://www-groups.dcs.st-and.ac.uk/~history/Mathematicians/Pascal.html. You might also search the archives at Casino Player magazine. Most early probability theory was developed to solve gambling problems. Some folk lore suggests that noblemen who liked to gamble commissioned mathematicians such as Pascal and Fermat to solve probability questions to aid in their wagering.