  We numerically show that time delayed coherent feedback controls the
statistical output characteristics of driven quantum emitters. Quantum feedback
allows to enhance or suppress a wide range of classical and nonclassical
features of the emitted quantum light. As exemplary quantum system, we use a
pumped cavity containing two emitters. By applying phase-selective feedback, we
demonstrate that photon antibunching and bunching can be increased in orders of
magnitude due to intrinsically and externally controllabe quantum
interferences. Our modelling is based on a fully non-Markovian quantum
simulation of a structured photon continuum. We show that an approximative
method in the Schr\"odinger picture allows a very good estimate for quantum
feedback induced features for low pump rates.
