A family from Basel that produced a stream of significant mathematicians. The best known are the brothers Jacques (or James or Jakob) and Jean (or John or Johann), and Jean’s son Daniel. Jacques Bernoulli (1654–1705) did much work on the newly developed calculus but is chiefly remembered for his contributions to probability theory: his Ars conjectandi was published posthumously in 1713. The work of Jean Bernoulli (1667–1748) was more definitely within calculus: he discovered l’Hôpital’s rule and proposed the brachistochrone problem. He was one of the founders of the calculus of variations. In the next generation, the work of Daniel Bernoulli (1700–82) was mainly in hydrodynamics.