1218 Milan forms a league to drive the Ghibellines from Lombardy. It is defeated at Ghibello; this causes great trouble between the Lombard nobles and citizens.
1221 The Milanese expel the nobles from the city.
1222 First war between Pisa and Florence. Foundation of the University of Padua.
1226 Renewal of the Lombard League for twenty-five years.
1227 Frederick II appoints Ezzelino da Romano to conduct warfare against the Guelfs in the Veronese March. They are defeated in Verona and Vicenza.
1228 Victory of Pisa over the united forces of Florence and Lucca near Barga.
1233 The cities of the Veronese March conclude the peace of Paquara through the efforts of the monk Giovanni da Vicenza. It lasts only a few days.
1234 Montferrat, Milan, Brescia, and other cities join the rebellion of Frederick’s son Henry. The Pisans renew war with the Genoese.
1236 Frederick takes the field against the Lombards. Ezzelino is in control in Verona, Vicenza, and Padua.