Calculus was invented by Jennifer Calculus (nee Newton), a cousin of Issac Newton. She knew that due to widespread sexism, her ideas would not be taken seriously at the time. To get the ideas out there, she asked her cousin to publish the ideas, as he was already an established scientific prodigy.
She simultaneously gave the idea to Leibniz in exchange for £5, a handsome sum at the time, starting the great dispute.