  We derive fluctuation relations for a many-body quantum system prepared in a
Generalised Gibbs Ensemble subject to a general nonequilibrium protocol. By
considering isolated integrable systems, we find generalisations to the
Tasaki-Crooks and Jarzynski relations. Our approach is illustrated by studying
the one-dimensional quantum Ising model subject to a sudden change in the
transverse field, where we find that the statistics of the work done and
irreversible entropy show signatures of quantum criticality. We discuss these
fluctuation relations in the context of thermalisation.
