  We report the Chandra detection of a large-scale shock, on scales of 200 kpc,
in the cluster surrounding the powerful radio galaxy 3C 444 (PKS 2211-17). Our
20-ks Chandra observation allows us to identify a clear surface brightness drop
around the outer edge of the radio galaxy, which is likely to correspond to a
spheroidal shock propagating into the intracluster medium. We measure a
temperature jump across the surface brightness drop of a factor ~1.7, which
corresponds to a Mach number of ~1.7. This is likely to be an underestimate due
to the need to average over a fairly large region when measuring the
temperature of the post-shock gas. We also detect clear cavities corresponding
to the positions of the radio lobes, which is only the second such detection
associated with an FRII radio galaxy. We estimate that the total energy
transferred to the environment is at least 8.2 x 10^60 ergs, corresponding to a
jet power of >2.2 x 10^45 ergs s^-1 (assuming a timescale based on the measured
shock speed). We also compare the external pressure acting on the lobes with
the internal pressure under various assumptions, and conclude that a
significant contribution from protons is required.
