Newton and Leibniz both came up with calculus independently, and then had a huge row over which one of them did it first. In the end, Newton got credited with its discovery and Leibniz is still credited with certain areas of it (like the product rule) and his notation is used more often.
They probably never actually fought like this, but I like to imagine them having it out with each other.
Oh, and although Leibniz is the most piratical-looking mathematician ever, I'd still have been rootin' for Newton. ^_^