  The results of gamma-ray observations of the binary system HESS J0632+057
collected during 450 hours over 15 years, between 2004 and 2019, are presented.
Data taken with the atmospheric Cherenkov telescopes H.E.S.S., MAGIC, and
VERITAS at energies above 350 GeV were used together with observations at X-ray
energies obtained with Swift-XRT, Chandra, XMM-Newton, NuSTAR, and Suzaku. Some
of these observations were accompanied by measurements of the H{\alpha}
emission line. A significant detection of the modulation of the VHE gamma-ray
fluxes with a period of 316.7+-4.4 days is reported, consistent with the period
of 317.3+-0.7 days obtained with a refined analysis of X-ray data. The analysis
of data of four orbital cycles with dense observational coverage reveals short
timescale variability, with flux-decay timescales of less than 20 days at very
high energies. Flux variations observed over the time scale of several years
indicate orbit-to-orbit variability. The analysis confirms the previously
reported correlation of X-ray and gamma-ray emission from the system at very
high significance, but can not find any correlation of optical H{\alpha}
parameters with X-ray or gamma-ray energy fluxes in simultaneous observations.
The key finding is that the emission of HESS J0632+057 in the X-ray and
gamma-ray energy bands is highly variable on different time scales. The ratio
of gamma-ray to X-ray flux shows the equality or even dominance of the
gamma-ray energy range. This wealth of new data is interpreted taking into
account the insufficient knowledge of the ephemeris of the system, and
discussed in the context of results reported on other gamma-ray binary systems.
