Calculus was developed during the 17th century. Many people contributed, but the lion’s share of the credit goes to two men who made great contributions to other areas of science and mathematics as well: Isaac Newton and Gottfried Wilhelm von Leibniz.
If you think that genius necessarily comes with grace, then you’re wrong. Central to the invention of calculus is a story of arrogance and jealousy. Newton had developed his method of fluxions, as he called his take on calculus, allegedly a few years before Leibniz developed his theory, but Leibniz’s work was published first. Leibniz had not been aware of Newton’s work, and had approached the subject in a completely different way, but this didn’t stop Newton from accusing Leibniz of theft.
Corresponding mostly via other people, learned journals and pamphlets, Leibniz continued to protest his innocence while Newton continued to vent his wrath. Newton indignantly claimed that “not a single previously unsolved problem was solved” in Leibniz’s work. Leibniz called a Newton supporter an idiot. A Royal Society commission was set up to arbitrate, but was completely biased towards Newton and unsurprisingly found in his favour. The author of the commission’s final report was none other than … Newton himself!
The controversy over the true inventor of calculus was never resolved in the men’s lifetimes and overshadowed the end of both of their lives. We would suggest that collaboration is generally better than competition in the world of Mathematics.