The Novara area was affected by the campaigns of conquest of the French kings from 1495 to 1526, until the arrival of the Spaniards under Charles V established a new equilibrium.
In 1535, the emperor granted the town as a fief to the Farnese family, but in actual fact it remained under Spanish control. Their intention to turn it into a fortress led to the destruction of the suburbs and religious settlements in the vicinity of the old walls.
The renewal of the city, which already became part of the property of Milan under the rule of the Visconti and then the Sforza, can be seen in Piazza delle Erbe and the façades of the ancient Casa della Porta and Casa Rognoni.
The castle also reflects a phase of building from the Sforza era, in line with the residential redevelopment of fortified structures that occurred in other parts of the Duchy of Milan.