  Presently under construction in Lund, Sweden, the European Spallation Source
(ESS) will be the world's brightest neutron source. As such, it has the
potential for a particle physics program with a unique reach and which is
complementary to that available at other facilities. This paper describes
proposed particle physics activities for the ESS. These encompass the
exploitation of both the neutrons and neutrinos produced at the ESS for high
precision (sensitivity) measurements (searches).
