English mathematician. The Bishop of London, and later of Durham, Tunstall was a key Catholic figure in the troubled years of the English Reformation. An outstanding classical scholar, he studied theology and law at Oxford, Cambridge, and Padua. Tunstall wrote De arte supputandi libri quattuor (1522), one of the first printed works published in England devoted exclusively to mathematics. It contained no original material, but was a very practical arithmetic text. He also composed many religious works.