  In the iron-pnictide material CeFeAsO not only the Fe moments, but also the
local 4f moments of the Ce order antiferromagnetically at low temperatures. We
elucidate on the peculiar role of the Ce on the emergence of superconductivity.
While application of pressure suppresses the iron SDW ordering temperature
monotonously up to 4 GPa, the Ce-4f magnetism is stabilized, until both types
of magnetic orders disappear abruptly and a narrow SC dome develops. With
further increasing pressure characteristics of a Kondo-lattice system become
more and more apparent in the electrical resistivity. This suggests a
connection of the emergence of superconductivity with the extinction of the
magnetic order and the onset of Kondo-screening of the Ce-4f moments.
