Martin Gouterman laid the foundations for understanding porphyrin spectroscopy with the fourorbital model, which successfully assigned key features of many porphyrin spectra. He and his coworkers also recognized that many spectra did not quite follow the four-orbital model; notable among these are so-called hyperporphyrins that exhibit both redshifted spectra and extra bands relative to normal porphyrins. They further identified underlying causes of these additional features, attributing them to charge-transfer transitions between the central coordinated atom (which is typically a metal) and the porphyrin ligand, in the form of either metal-to-ligand charge transfer (MLCT) or ligand-to-metal charge transfer (LMCT) transitions. They later identified charge transfer transitions in metal-free porphyrins involving different parts of the porphyrin itself. In a perspective on hyperporphyrins, we have described different pathways of charge transfer between meso-aryl groups and the heterocyclic core in free-base porphyrins. In many cases, the hyperporphyrin effect is initiated or amplified by protonation or deprotonation reactions. For example, a particularly dramatic redshift is observed upon protonation of the central nitrogens of meso-tetrakis(4-aminophenyl)porphyrin (H2[TAPP]), with the lowest-energy band of H2 [TAPP] shifting from 669 nm to 813 nm to {H4[TAPP]} 2+ (note that the peripheral amino groups remain unprotonated). The strong delocalization that generates the hyperporphyrin effect can be illustrated with quinone-like resonance forms that show conjugation between the aminophenyl groups and the protonated porphyrin. Gouterman and coworkers performed semiempirical calculations that supported this charge transfer; 8 more recently, we published a TDDFT study, further refining the spectral assignments for {H4[TAPP]} 2+ . 9