  In order to probe the changes in the valence state and magnetic properties of
Eu metal under extreme pressure, x-ray absorption near-edge spectroscopy, x-ray
magnetic circular dichroism and synchrotron M\"ossbauer spectroscopy
experiments have been carried out. The M\"ossbauer isomer shift exhibits an
anomalous pressure dependence, passing through a maximum near 20 GPa. Density
functional theory has been applied to give insight into the pressure-induced
changes in both Eu's electronic structure and M\"ossbauer isomer shift.
Contrary to previous reports, Eu is found to remain nearly divalent to the
highest pressures reached (87 GPa) with magnetic order persisting to at least
50 GPa. These results should lead to a better understanding of the nature of
the superconducting state found above 75 GPa and of the sequence of structural
phase transitions observed to 92 GPa.
