  A detailed model of galactic evolution is proposed to explain both the iron
content of the Intra-Cluster Medium (ICM) and of the ellipticals pertaining to
the cluster. SNII are responsible for the production of Fe in the galaxies and
of its partial ejection in the surrounding medium. A high formation rate of
massive stars only ($m>3~{\rm M_{\sun}}$) at the very early stage of evolution
of ellipticals, reminiscent of starburst galaxies, is advocated. The high rate
of SNII explosions induces a powerful galactic wind, followed by a more
quiescent evolution where stars are formed, with a normal Initial Mass Function
(IMF), from the enriched gas remaining after the wind phase and from the gas
restored by the longest living stars produced during the early phase. Most of
the iron is produced by the high-mass stars created in the early burst phase.
