Abstract: The present disclosure relates to a core (12) of a transformer (10) which includes at least one leg (14) around which a winding (18) can be wound. The leg (14) includes a first core component (26) made of an amorphous material and a second core component (32) made of electrical steel. The leg (14) extends in a first direction (50) which is perpendicular to the first winding axis (20) and in a second direction (52) which is perpendicular to the first winding axis (20) and to the first direction (50), when the winding (18) is wound around the leg (14). The extension of the leg (14) in the first direction (50) is greater than the extension of the leg (14) in the second direction (52). The leg (14) is tapered in the first direction (50) and/or the second direction (52). The present disclosure also relates to an assembly, a transformer, and a method of manufacturing a core (12).