Calculus was independently discovered in the late 17th century by two great mathematicians: Isaac Newton and Gottfried Wilhelm Leibniz. Both are credited as the founders of calculus, with Newton being the first to develop his results (though he published later) and Leibniz publishing first. Newton focused more on the application of calculus to physics, while Leibniz developed much of the modern notation used today. Their independent discoveries led to a famous controversy over priority, but it is now generally accepted that both contributed significantly and independently to the development of calculus.
Before Newton and Leibniz, important precursors to calculus appeared in ancient Greece with mathematicians like Archimedes, who developed methods akin to integral calculus, and in India and the Middle East where elements of calculus were also explored. However, the formal development as a distinct mathematical discipline took place with Newton and Leibniz in the 17th century.