Although methods of calculating areas and volumes dated from ancient Greek mathematics, the principles of integration were formulated independently by Isaac Newton and Gottfried Wilhelm Leibniz in the late 17th century, who thought of the area under a curve as an infinite sum of rectangles of infinitesimal width.

Who discovered integrals?

1675: Gottfried Leibniz writes the integral sign ∫ in an unpublished manuscript, introducing the calculus notation that's still in use today. Leibniz was a German mathematician and philosopher who readily crossed the lines between academic disciplines.

Where did integrals come from?

The foundations for the discovery of the integral were first laid by Cavalieri, an Italian Mathematician, in around 1635. Cavalieri's work centered around the observation that a curve can be considered to be sketched by a moving point and an area to be sketched by a moving line.