Ultrafast experiments utilising femtosecond optical and X-ray pulses have been extensively used to resolve the dynamics of excited-state molecules. However, the complexity of the time-resolved (TR) data and its analysis can be very high-especially in complicated cases such as transition metal (TM) complexes-which often leads to ambiguities and contradictions in mechanistic interpretations. This is showcased by the light-induced low-spin (LS) → high-spin (HS) transition in Fe(II) polypyridyl complexes, which have attracted grand attention due to its potential importance in new technologies, e.g., molecular data storage. From femtosecond transient optical absorption (TOAS), X-ray absorption and X-ray emission spectroscopy (XES) investigations, it is known that irradiation of the prototypical [Fe(bipy) 3 ] 2+ complex (bipy = 2,2'-bipyridine) by visible light promotes the system from the LS ground state ( 1 GS) into singlet metal-to-ligand charge transfer states ( 1 MLCT), which in turn leads to conversion into the quintet HS state in <200 fs. On the other hand, it is still not clear according to which of the following two mechanisms is the HS state populated: i) a direct 3 MLCT → 5 MC (HS) one, or ii) via a sequential 1,3 MLCT → 3 MC → 5 MC pathway with a triplet metal-centered intermediate ( 3 MC).