Cosimo is forced to take control when his father, Giovanni, dies suddenly; his first action is to take over the family bank.

War throws Florence into chaos, and Piero, Cosimo's only son, is anxious to join the fight, but Lucrezia, the boy's mother, tries to prevent him from going.

The family hopes for refuge in the countryside from the contagion, but Marco remains in Florence.

In front of the Signoria, Albizzi accuses Cosimo of plotting to become the city dictator.

Circumstances continue to go downhill in Florence while the family remains in exile; Albizzi takes control of Florence.

The family returns to Florence in triumph; Albrizzi winds up in prison for trying to take over the city.