How Many Divisions Has the Pope?
(1198 - 1218)
The War of the Holy League
What began as encouragement turned to full-fledged participation with the formation in 1199 of the Holy League, or the League of Rome, a triple alliance between Pope Pagenellus, Emperor Heinrich, and Louis of France. Its stated aim was the removal of the Rossi clan from power; in the long term, it meant to divide up all Milanese holdings between the three allies, including those taken from the increasingly-isolated Byzantine Empire. The Papacy held claim on Florence, and it was there that men were sent the following year to lay siege, nearly capturing it in a hasty assault.
That same year, Louis himself rode into Italy, invigorated by and basking in the glory of his successful capture of Antioch. For the better part of a decade, his French knights and an Imperial army under the command of the Bavarian count Otto von Kassel would keep a strong hold on most of northern Italy. While battles would rarely amount to amount to more skirmishes, the countryside suffered terribly, and the Milanese treasury dwindled steadily for lack of trade and need of soldiers. A foray into eastern Imperial territory in 1206 failed to draw von Kassel's forces out of Italy, but it did accomplish something unexpected: the capture of Vienna.
A major change in the Rossis' fortunes came in 1208 when, at the Battle of Alessandria, Louis himself was killed during a failed cavalry charge. This death (as well as the crushing defeat it inspired) would mark the end of major French activity in Italy; within a year, Louis' son Philip would have to fight a defensive war against the English for the very crown of France. Emperor Heinrich, to his credit, wouldn't relent from the war on Milan. In 1210 he sent men to retake Vienna; rather than endure an attack, the small Milanese garrison, which had been bleeding the citizens dry with war taxes, put the city to the torch and abandoned it to an anarchic rabble. Several thousand died and most of Vienna's infrastructure was destroyed. When the Imperial forces arrived, it was not to a Milanese stronghold but to a destroyed city under the control of a peasant mob.
After the Burning of Vienna, the war in Italy largely returned to the status quo. Von Kassel kept his army stationed in and around the Po Valley, while the Papacy kept alive the threat of a second, stronger attack on Florence. After strengthening the garrison at Genoa, Duke Catelano took a risky move and ordered its governor, his younger brother Amero Rossi, to march westward to Marseille and take it from a weakened France. He did his duty, and in 1216 Milanese territory covered another long stretch of Mediterranean coastline. Milanese diplomats would later make a failed bid to convince the Duke of Toulouse to betray his King; further advancement into France, it seemed, would have to remain military.
In a surprise attack that shocked and humiliated Milan, French ships sailed into the harbor at Marseille the following year and destroyed most of their navy at anchor. Ships could be and would be rebuilt, of course, but the timing of the attack could not have been worse. For in 1218, across clear seas and two decades overdue, a fleet of Spanish ships sailed to Corsica.