Answer:
Isaac Newton published a partial account of his theory of calculus in 1693 and a full account in 1704. According to his friends he had worked it out years before. The late date of publishing led to controversy at the time.
Leibniz, a German mathematician published his method for calculus in 1684 before Newton. Leibniz insisted he had discovered calculus first, Newton disputed this strongly claiming Leibniz had stolen his work. This whole dispute lead to a general dislike and distrust of German scientists by English scientists, and of English scientists by German scientists.
Most modern historians believe Newton and Leibniz discovered calculus independently.