  Emission lines in X-ray spectra of clusters of galaxies reveal the presence
of heavy elements in the diffuse hot plasma (ICM) in virial equilibrium in the
dark matter potential well. Thanks to the X-ray satellites Chandra and
XMM-Newton we are now able to measure with good accuracy the distribution and
evolution of Iron up to redshift z ~ 1.3. The capability of studying the
chemical and thermodynamical properties of the ICM in high redshift clusters is
an efficient tool to constrain the interaction processes between the cluster
galaxies and the surrounding medium. We confirm that the ICM is already
significantly enriched at a look-back time of 9 Gyr, and find that the Iron
abundance change with redshift as (1+z)^(-1.25), implying an increase of a
factor of ~2 with respect to z=1.3. This result can be explained by a prompt
enrichment by star formation processes in massive ellipticals at z>2, followed
by a slower release of enriched gas from disk galaxies into the ICM, associated
to a morphological transition from disk to S0.
