  We consider the non-equilibrium dynamics after a sudden quench of the
magnetic field in the transverse field Ising chain starting from excited states
of the pre-quench Hamiltonian. We prove that stationary values of local
correlation functions can be described by the generalised Gibbs ensemble (GGE).
Then we study the full time evolution of the transverse magnetisation by means
of stationary phase methods. The equal time two-point longitudinal correlation
function is analytically derived for a particular class of excited states for
quenches within the ferromagnetic phase, and studied numerically in general.
The full time dependence of the entanglement entropy of a block of spins is
also obtained analytically for the same class of states and for arbitrary
quenches.
