A magnetic fault current limiter core (10a) comprising at least one first magnetic element (12) and at least one second magnetic element (14), the magnetic elements (12,14) being arranged to define a substantially parallel array of magnetic elements (12,14), the or each first magnetic element (12) including a soft magnetic material and the or each second magnetic element (14) including a hard magnetic material, wherein the or each soft magnetic material in a non-saturated state has a higher magnetic permeability than the or each hard magnetic material.