In 1328, after accusations of betrayal from his brother Marco, as well as that of the assassination of his brother Stefano Visconti, the emperor had him imprisoned in Monza. Galeazzo was freed in March 1328 and took shelter under the other Ghibelline leader of Italy at the time, Castruccio Castracani. However, he died at Pescia in August 1328.
Galeazzo's reign came to an end in 1328 when he was imprisoned by his brother Marco and accused of Stefano Visconti's murder. He escaped in March 1328 but eventually found refuge with Castruccio Castracani, only to die at Pescia later that year.