Gottfried Wilhelm Leibniz
(1 July 1646 – 14 November 1716)

German mathematician, philosopher, scientist and diplomat who is credited, alongside Sir Isaac Newton, with the invention of calculus in addition to many other branches of mathematics, such as binary arithmetic, and statistics.

In this day in 1675, Leibniz makes the first use of the longs (∫) as a symbol of the integral in calculus.