| Let K be a finite extension of Q and let R be the integral closure of Z in K. Let L be a Galois extension of K with group G and ring of integers S. Galois module theory is the branch of number theory which seeks to describe S as a module over the group ring RG. In this talk we develop the basic notions of Galois module theory and show how Hopf orders can be used to describe the Galois module structure of S. |