The dungeons

Prisoners in the castle were almost always high-ranking personages who often left evidence of their stay in the graffiti that is still visible in the largest dungeons. Already in 1388, the chronicles describe how Obizzo d'Este, nephew of the then marquis Alberto, was imprisoned in the castle along with his mother Beatrice da Camino and many others involved in a plot obviously intended to seize power, which came to a bloody end with a series of bloodcurdling executions.
In 1425 Ugo d'Este and Parisina Malatesta, the son and young wife of Nicolò III were imprisoned in the castle and then beheaded, guilty not of a conspiracy but of love between young two people of the same age that the marquis could not forgive. In the basement of the Marchesana Tower, theatre of the tragic end of the two young lovers, a frescoed triptych, now conserved in the museum, shows the Virgin Mary between two saints. The pictures seem to have been realised to atone for the crime and to consecrate the place of execution. As we will see, under the Este family the castle, although enriched with other elements, would never lose its military function and that of being a place of detention for crimes which may be defined as political.
Even after the transformation, in the part of the castle that was lived in, the ground floor would always be used to defend its illustrious inhabitants while the rooms below would continue to be inhabited by those prisoners who would have to be kept under special surveillance.
Borso d'Este imprisoned and executed within the castle many of those who took part in the rebellion waged against him by the Pio family, lords of Carpi in 1469. In 1506, once again a plot saw the castle used to lock people away.
This time Giulio and Ferrante d'Este, guilty of having plotted against their brother Alfonso, designated heir to their father Ercole I's title of duke. Some of the plotters were executed immediately; Ferrante was imprisoned and died just a few years later, while Giulio would be kept in solitary confinement in the Torre dei Leoni until 1556. In various rooms prisoners have left graffiti as a memorial to their "sad fate". They have continued to do so after the Este family, in the Papal era, the Napoleon one and even into the last century.