The Bolognese Confraternity of Santa Maria della Morte was founded in 1336 and is the oldest Italian Company of Justice with the specific mission to reconcile, calm, and save the souls of those prisoners destined for the gallows. Its rich laudario – 211 texts in total, half still unpublished – is known now in some thirteen manuscript sources, mostly dating from the second half of the 15th century. In more than a quarter of these very diverse poems (paraphrases of official Latin prayers, litanies, contrasti, laude, sacre rappresentazioni, etc.), Mary is the central figure evoked. This article explores her intermediary role between heaven and earth as conveyed in this corpus, a role that appears strictly related to the parallel developments of thought realised both in civic commercial society and legal thinking. The Virgin there becomes the guarantor of aequitas, the rational human corrective necessary for the aseptic application of rigor iuris: this is particularly meaningful in Bologna, a ‘Marian’ city famous for the presence of the oldest university chair of jurisprudence in the Western world. Mary’s role of super partes mediator becomes even more authoritative in this city often shaken by feuds. Inevitably, many conflicts arose from its local complex government where papacy, seignories, powerful local families, and bourgeoisie constantly rivaled each other, at least from the end of the 13th century.