  VER J0521+211 (RGB J0521.8+2112) is one of the brightest and most powerful
blazars detected in the TeV gamma-ray regime. It is located at a redshift of
z=0.108 and since its discovery in 2009, VER J0521+211 has exhibited an average
TeV flux exceeding 0.1 times that of the Crab Nebula, corresponding to an
isotropic luminosity of $3\times10^{44}$ erg s$^{-1}$. We present data from a
comprehensive multiwavelength campaign on this object extending between
November 2012 and February 2014, including single-dish radio observations,
optical photometry and polarimetry, UV, X-ray, GeV and TeV gamma-ray data
(VERITAS, MAGIC). Significant flux variability was observed at all wavelengths,
including a long-lasting high state at gamma-ray energies in Fall 2013.
Nightly-resolved spectra at X-ray and TeV energies are be presented, and
emission mechanisms explaining the observed flux and spectral variability are
discussed.
