Daniel Bernoulli was one of the founders of mathematical physics. His father Johann taught him, but (over-competitive and jealous) tried to claim the honours for Daniel’s work on hydrodynamics. Goldbach, Clairaut, Maupertuis and Euler were all close mathematical friends of Bernoulli’s, living fruitfully intertwined lives. Euler, a friend from youth, lodged and worked with him in St Petersburg (he was asked to bring tea, coffee and brandy from Switzerland). Goldbach helped him get an early paper published, and like Lagrange and Clairaut, kept up an important correspondence. König was one of his students.