Reconstructing the volume and tephra dispersal from volcanic super-eruptions is necessary to assess the widespread impact of these massive events on climate, ecosystems and humans. Recent studies have demonstrated that volcanic ash transport and dispersion models are unrivaled in accurately constraining the volume of material ejected and provide further insight about the eruption dynamics during these gigantic events. However, the conventional simplified characterization of caldera-forming supereruptions as a single-phase event can lead to inaccurate estimations of the eruption dynamics and its impacts. Here, we apply a novel computational inversion method to reconstruct, for the first time, the two phases of the largest eruption of the last 200 ky in Europe, the Campanian Ignimbrite (CI) super-eruption. Additionally, we discuss the eruption’s contribution to the Middle to Upper Paleolithic transition by evaluating its environmental and climate implications.