  The H.E.S.S. (High Energy Stereoscopic System) phase I is comprised of four
Imaging Atmospheric Cherenkov telescopes, for observation of galactic and
cosmic sources of very high energy gamma rays. Its installation in the Khomas
highlands, Namibia has been completed in December, 2003. The first of these
telescopes was installed in June 2003, and data-taking has proceeded since that
time. The HESS telescope system provides a significant improvement in
sensitivity and a threshold for detection below that of previous Imaging
Atmospheric Cherenkov Telescopes. The characteristics for the phase-I will be
presented, together with plans for phase-II of the experiment, comprised of a
large telescope in the centre of the current phase-I providing a lowered
threshold and increased sensitivity. We can observe AGNs up to redshift 0.5
with HESS and 2-3 with HESS Phase-2, which provides a unique capability for
study of spectral and temporal characteristics on timescales of several hours
or even less than 1 h (depending on the strength of flares). We will present
the first results from a number of southern AGN observed during the
installation of the phase-I, in particular concerning the detection and
spectral properties of the AGN PKS2155$-$305.
