John Wallis, an English mathematician, born at Ashford, Kent, Nov. 23, 1616, died Oct. 28, 1703. He was educated at Cambridge, took holy orders in 1640, and in 1641 became chaplain to Sir William Darley. When the civil war broke out he took the parliamentary side, and deciphered the intercepted letters of the royalists. In 1643 the sequestrated living of St. Gabriel, Fenchurch street, London, was given to him, and in 1644 he was appointed a secretary of the assembly of divines at Westminster, of the proceedings of which he wrote an account. He was among the first, who joined the meetings in 1645 which afterward gave rise to the royal society. In 1649 he was appointed Savilian professor of geometry at Oxford. He had a mathematical controversy with Hobbes, carried on by pamphlets from 1655 to 1663. In 1658 he became keeper of the university archives. After the restoration, which he favored, he was named one of the king's chaplains in ordinary. His Opera Mathematica were published in 3 vols. (Oxford, 1697 - '9); the most important of them is the Arithmetica Infinitorum, in which he foreshadowed the binomial theorem and the method of fluxions.

He wrote also Grammatica Linguoe Anglicanoe (1653), and Institutio Logical (1687).