Pisa was ruled at that time by the Gambacorta family, with an old merchant named Pietro at their head.

This man had a friend and secretary called Jacopo Appiano, whom the Visconti persuaded to turn Judas, and to entrap and murder his benefactor and his children.

The assassination took place in 1392.

In 1399 Gherardo, son of Jacopo Appiano, who held Pisa at the disposal of Gian Galeazzo, sold him this city for 200,000 florins.[6] Perugia was next attacked.

Here Pandolfo, chief of the Baglioni family, held a semi-constitutional authority, which the Visconti first helped him to transmute into a tyranny, and then, upon Pandolfo's assassination, seized as his own.[7] All Italy and even Germany had now begun to regard the usurpations of the Milanese despot with alarm.