  H.E.S.S. -- The High Energy Stereoscopic System-- is a new system of large
atmospheric Cherenkov telescopes for GeV/TeV Gamma-ray astronomy. This paper
describes the trigger system of H.E.S.S. with emphasis on the multi-telescope
array level trigger. The system trigger requires the simultaneous detection of
air-showers by several telescopes at the hardware level. This requirement
allows a suppression of background events which in turn leads to a lower system
energy threshold for the detection of Gamma-rays. The implementation of the
H.E.S.S. trigger system is presented along with data taken to characterise its
performance.
