On 3 May 1385, the Ferrarese people, driven to desperation by taxes and flooding that had brought ruin upon them, took themselves to the Marquis Niccolò II d'Este's palace to ask the advice of Tommaso da Tortona, the high official held to be responsible for this grave situation.

This episode, which resulted later in the death of the leaders of the revolt, convinced the Marquis that the family's palace (which is now the Palazzo Comunale) was insufficient to guarantee the security of the nobility in the event of riots.

The architect Girolamo da Carpi gave the castle the external appearance which can be still seen today, although the interior has been remodelled several times across the ages.

After the departure of the Este to Modena, the castle became the residence of the Papal Legate who administered the Ferrarese territory as civil governor (for a maximum term of four years).

In particular, at the top were portraits of all the ancestors (real and legendary) of the Este family: the only ones surviving, considerably damaged but still discernible, have been detached and placed under the portico on the east side of the courtyard.

On one wall is seen the portrait of Cristoforo di Messisbugo, the most famous of the Este's 'Scalcos' – the Scalco was the official who supervised many of the practical aspects of court life, organised spectacles, directed the kitchens, and readied things whenever necessary for moves to and from the family's country residences, etc.

[7] Shortly after entering a narrow corridor, on the left the low deep doorway that leads into the Don Giulio's dungeon, once allotted for a cell and perhaps also a torture chamber.

Notably Giulio d’Este was shut up in this cell for many years; he was the legitimate brother of Alfonso I and the lead actor in a famous and unhappy affair.

After seven years of marriage that had been generally quite calm, she ended up falling in love with her stepson Ugo, son of the Marquis and Stella dei Tolomei, and he with her.

Before 1385, since at least one hundred years, on the site where the Castle of Saint Michael was built, an old watchtower stood to defend the northern line of the city walls and, more exactly, the near strategic gate called of the Lion, beyond which a small homonymous district extended.

At that period the town had developed alongside the left bank of the main branch of the river, whose course in that point opened eastward to form a vast delta.

Thus, from a high, rectilinear square-planned tower, intended for surveillance and sighting, it turned into a small fort with a much wider base and larger battlements on the first floor, well-equipped according to the latest military defensive techniques.

A ramp, that ran along three sides of the stronghold, allowed access to the battlements and was meant to facilitate transport of weapons, artillery and other such loads with the help of animals.

An old tradition argued that Renée de France – wife of Duke Ercole II of Este who had Calvinist sympathies – ordered this particular decoration, without sacred images.

At the end of the main piazza (on the right the cathedral, on the left the Palazzo Ducale, behind which are poking out the towers of the Castle), is portrayed a gate which closes it off, while behind the built-up areas the old walls can be seen.

In the 19th century Cardinal Tommaso Benetti had the ceiling decorated with an epic scene: Hector leaving his son and his wife Andromache (Iliad Book VI).

The large panel reproduces a fresco with a representation of Estense territory: the Duchy of Ferrara at the centre, with Modena and Reggio on the left.

The wall designs in tempera are dedicated to images of Diana and other divinities, whereas on the ceiling, between large sections supporting light architectural structures, the four seasons are illustrated in small panels.

Created for Ercole II (1534–1559) to deal with the business of government, it still displays its splendid original ceiling with painted and gilded lacunars (recessed panels), one of the most beautiful in this style in the whole of Italy.

The four pictures are to be read clockwise, starting from the side nearest the Sala del Governo: in the first one, Lucrezia d’Este, sent by the Duke of Ferrara, is conversing with Cardinal Pietro Aldobrandini, the Pope's nephew; in front, two secretaries are drawing up the Agreement which was then to be signed by these two plenipotentiaries.

In the second, Duke Cesare d'Este, surrounded by dignitaries, leaves the city he has lost, on horseback, bound for Modena, which he had declared the new capital of his State.

In the fourth, finally, one of the many festivities organised in honour of Pope Clement VIII, come to take possession of the city: in the castle moat, ladies from Comacchio race the typical boats of the lagoons, the batane.

The enormous area once covered by water and marshes has for mostly disappeared today, in the wake of the great land reclamation works that were concluded in the 1930s.

The lower part is however occupied by a decoration made in 1857 on the occasion of the visit of Pope Pius IX, which completely hid the earlier paintings.

More coats of arms and some views of the Ferrarese territory of that time: the city of Ferrara (the Castle), Comacchio (the Trepponti), Cento (the main square), Lugo di Romagna (the porticoes), Pomposa Abbey and Bagnacavallo.