Lombard League (Wikipedia):
The Lombard League was an alliance formed around 1167, which at its apex included most of the cities of northern Italy (although its membership changed in time), including, among others, Milan, Piacenza, Cremona, Mantua, Crema, Bergamo, Brescia, Bologna, Padua, Treviso, Vicenza, Venice, Verona, Lodi, and Parma, and even some lords, such as the Marquis Malaspina and Ezzelino da Romano. The League was formed to counter the Holy Roman Empire's Frederick I, who was attempting to assert Imperial influence over Italy. Frederick claimed direct Imperial control over Italy at the Diet of Roncaglia (1158). The League had the support of Pope Alexander III, who also wished to see Imperial power in Italy decline. At the Battle of Legnano on May 29, 1176, Frederick I was defeated and, by the Peace of Venice, which took place in 1177, agreed to a six-year truce from August,1178 to 1183, until the Second Treaty of Constance, where the Italian cities agreed to remain loyal to the Empire but retained local jurisdiction over their territories.
The Lombard League was renewed several times and after 1226 regained its former prestige by countering the efforts of Frederick II to gain greater power in Italy. These efforts included the taking of Vicenza and the Battle of Cortenuova which established the reputation of the Emperor as a skillful strategist. He misjudged his strength, rejecting all Milanese peace overtures and insisting on unconditional surrender. It was a moment of grave historic importance when Frederick's hatred coloured his judgment and blocked all possibilities of a peaceful settlement. Milan and five other cities held out, and in October 1238 he had to unsuccessfully raise the siege of Brescia. Once again receiving papal support, the Lombard League effectively countered Frederick's efforts. During the 1249 siege of Parma, the Imperial camp was assaulted and taken, and in the ensuing Battle of Parma the Imperial side was routed. Frederick lost the Imperial treasure and with it any hope of maintaining the impetus of his struggle against the rebellious communes and against the pope. The League was dissolved in 1250 once Frederick died.
The Following paragraph is from a book called 'Modern Italian grammar: a practical guide', and clarifies and simplifies a number of things:
"When, in 1152, Frederick I, known as Redbeard, became King of Germany, he decided to suppress the rebellious City States, He Carred out five raids in Italy; in the first (1154) he suppressed the rebellion in Rome, and had himself crowned emperor; in the second he conquered Milan and with due ceremony reaffirmed the rights of the emperor (1158) in the third he besieged and destroyed Milan (1163) in the fourth he occupied Rome (1168) and in the fifth he was defeated at Legnano by the Lombard League (an alliance between the City States, set up in Pontida in1167, and supported by Pope Alexander III). For this reason he was forced to recognize the freedom of the City States, with the peace treaty of Constance (1183)."
The critics of Padanian identity have gone after trivial facts, to try to underscore the significance of events like the Battle of Legnano. For example, whether or not there was a specific "oath" taken at the formation of the Lombard League in Pontida, Lombardy. That's how the game is played. A people's history needs to be trivialized or absorbed and molded into what is "politically correct." For example, references to "the Italian League," or that it was "for Italian freedom" even though Italy never even existed before. If the history of other groups were to be attacked, it might be answered with calls of "bigotry" or "racism." However, if you're unfortunate enough to be "politically incorrect," then you don't receive this type of protection. You're on your own.
A perfect example of this is if we look at the War of the Sicilian Vespers. Historically, it is referred to as a struggle by the Sicilian people for Sicilian freedom, which it was. However, why is the Battle of Legnano any different? It was a war carried out by Lombardo-Venetian people for Lombardo-Venetian freedom. Why the double standard?