Solar flares are rapid, unpredictable and violent episodes of intense energy release in the Sun's atmosphere. The energy source for flares is the stressed magnetic field of the Sun's outer atmosphere, or corona. The main energy sink is the radiation emitted by the Sun's lower atmosphere, particularly the thin, complex plasma layer called the chromosphere. The chromosphere provides many of the remote-sensing diagnostics for the physical processes involved - magnetic reconnection, particle acceleration, plasma heating, and mass motion - as well as for the magnetic field and its evolution. It is also a region where the plasma properties vary rapidly and by orders of magnitude, presenting many significant observational and theoretical challenges. I will discuss what we have learned about solar flares from the chromospheric standpoint and will also highlight the gaps in our understanding that are the focus of current and future satellite missions, telescopes, and modelling efforts.