  A brief overview of the development of neutrino detectors for long-baseline
oscillation experiments at accelerators and reactors is presented. Basic
principles and main features of detectors of running accelerator experiments
T2K and NOvA sensitive to a first level of CP violation and neutrino mass
hierarchy, and reactor experiments Daya Bay, RENO and Double Chooz which
measured the mixing angle \theta_13 are discussed. A variety of different
experimental techniques is proposed and developed for the next generation
oscillation experiments: a 20 kt scintillator detector for the reactor
experiment JUNO, a 0.52 kt water-Cherenkov detector Hyper-Kamiokande, and a
massive liquid argon time-projection chamber neutrino detector envisaged for
the DUNE experiment. Present status of these detectors, recent progress in R&D
and future prospects are summarized in this paper.
