[en] We have measured the resistivity and magnetisation of several samples of the Eu_1-xCa_xB₆ series under pressure in order to probe the evolution of itinerant electron ferromagnetism in CaB₆ from a localised moment ordered state in EuB₆. Starting with pure EuB₆, the Curie temperature T_C is reduced upon increasing x. In particular, we have investigated the magnetic field and pressure dependence of T_C, which is enhanced by both of these externally tuneable control parameters. At T_C, there is a large peak in the resistivity, which is eliminated by moderately strong magnetic fields. (author)