Charles II of Naples intervened for the defence of John's realm, hoping in the end to install him as his vassal in Piedmont.

With Charles and Thomas, who renewed the investiture of Dogliani, John fought against Alessandria and Asti to recuperate territories lost by his father.

[3] The league John formed against Matteo Visconti succeeded in chasing him from the city in 1302 and obtaining the submission of Asti in 1303.

A few days after dictating his testament, which entrusted his lands to the commune of Pavia, he died and was buried with his forefathers in the abbey of Santa Maria di Lucedio.

However, after the funeral rites were completed, some of John's ministers murdered Emanuele, without a trial confirming or denying his guilt, by stabbing him repeatedly and then eating his flesh.