Disbarred as a woman from formal study, Germain sent Lagrange a term-paper under a male pseudonym. Greatly impressed by it, he asked to meet its author, was duly astonished to discover her gender, and took her on as his protégée. Cauchy and (especially) Fourier became supportive friends, not least in the face of deliberate frostiness from Poisson and his allies. She wrote to Legendre about number-theory, the ensuing correspondence amounting to a full collaboration. She and Gauss corresponded for some years; she helped ensure his safety, while he proposed her for an honorary degree, the first to a woman.