Leonhard Euler — The Master of Us All

Euler (1707–1783) is the most prolific mathematician in history, having filled 92 volumes with his work. He invented much of modern mathematical notation: f(x) for functions, e for the base of natural logarithms, i for the square root of −1, Σ for summation, and the use of π for the circle constant. He continued producing mathematics at an undiminished rate after going completely blind. His identity e^(iπ) + 1 = 0 links five of the most important constants in all of mathematics in a single equation.