Sophie Germain’s favourite problem

Sophie Germain’s favourite unsolved problem, to which she devoted much of her research, is known as Fermat’s Last Theorem. This was a centuries-old mystery that catalysed the development of modern number theory, and that was finally resolved at the end of the 20th century in a stunning breakthrough by Sir Andrew Wiles. This talk gives a gentle introduction to the old and new mathematics surrounding Fermat’s Last Theorem.