  The HEGRA system of 4 Imaging Atmospheric Cherenkov Telescopes (IACTs) has
been used since March 1997 for a comprehensive study of the gamma-ray emission
from the BL Lac object Mkn 501 in the energy range above 500 GeV. Taking
advantage of the unique capabilities of the IACT system, i.e. an unprecedented
flux sensitivity in the TeV energy range and an unique energy resolution of
better than 20% for individual TeV photons, detailed information about the
temporal and spectral characteristics of the source during its spectacular
bright phase in 1997 is reported. Further more, using the large HEGRA and Rossi
X-Ray Timing Explorer All Sky Monitor (RXTE ASM) data bases, the correlation of
the X-ray and the TeV activity of the source is discussed. Finally, an outlook
over present and future activities is given.
