The man who invented the concept of pi: William Jones and his circle

William Jones was important in his lifetime primarily for three things: he was the first person to use the Greek letter π in its modern sense. Additionally, he had acquired such a significant archive of manuscripts that he was appointed to the Royal Society committee, to investigate the invention of calculus. Finally, he was influential as communicator in a network of mathematicians, astronomers and natural philosophers in the early eighteenth century.