Guido Torelli was the forefather of the rich and noble family of Torelli who ruled over Guastalla and Montechiarugolo until the seventeenth century. He belonged to a family of strong military traditions that had distinguished itself in Mantua in the service of the Gonzaga family, in which Guido himself had lent his arms.
After the unrest due to the death of the Duke of Milan, many duchies in the Parma area revolted to the central domain but Guido, demonstrating broad diplomatic skills and rightly prefiguring the fate of this crisis, chose to ally with the Visconti. This proved a happy choice because, once victorious these, in the person of Giovanni Maria Visconti, October 3, 1406, rewarded Guido Torelli with the investiture of the feuds of Montechiarugolo and Guastalla.
All this honor was also due to Guido's evident participation in numerous battles waged in those years by the Visconti, including the liberation of Naples from the Aragonese of 12 April 1424.
On 6 July 1428, Filippo Maria Visconti decided to further reward Guido Torelli, raising the two fiefdoms already acquired as lordship to the county, subsequently obtaining also other exclave territories, such as Casei Gerola, Cornale, Settimo and Villareggio, even if Guido settled in Milan. In that year the daughter Antonia married in marriage with Pier Maria II de 'Rossi, count of San Secondo.
Guido Torelli died in 1449, prescribing that his successors should be named both sons, Cristoforo and Pietro Guido. He was buried in the church of San Francesco in Mantua.