Isaac Barrow

Isaac Barrow, who lived from 1630 to 1677, was an English Christian theologian and mathematician generally credited with an early role in the development of infinitesimal calculus, in particular a proof of the fundamental theorem of calculus. Born in London, the son of a linen draper, he studied at Charterhouse, Felsted School and Trinity College, Cambridge, won a fellowship in 1649 and, after refusing to sign the Engagement to uphold the Commonwealth, spent four years travelling through France, Italy and Turkey. Ordained at the Restoration in 1660, he became Regius Professor of Greek at Cambridge, professor of geometry at Gresham College in 1662 and in 1663 the first Lucasian Professor of Mathematics, resigning that chair in 1669 in favour of his student Isaac Newton. His Lectiones Opticae et Geometricae of 1669 is his most important work in mathematics; he was the first to calculate the tangents of the kappa curve and the first to find the integral of the secant function in closed form. He was made a Doctor of Divinity in 1670, became Master of Trinity College in 1672, founded its library, and died in London in 1677 at the age of 46.