I’ve been working on this project on and off for a few months. I recently got back into Europa Universalis IV and played a very enjoyable campaign as Milan. A few years into the game, I got the random event “Talented and Ambitious Daughter” granting my otherwise childless ruler a female heir with a 6/6/6 skill set (first time this has happened to me as well). Seeing as Filippo Maria Visconti had a baseborn daughter in real life named
Bianca Maria, I rolled with it and proceeded to unify Northern Italy under the Visconti banner. As it's partially based on a computer game, the PoD isn't that strong, nor do I claim this to be a very plausible timeline. Nevertheless, I hope you enjoy it!
Excerpt from pages 46-47 of Palgrave's Concise Historical Atlas of Italy (2020):
The life and times of Bianca Maria Visconti were marred by triumphs and tragedies. A lifetime mirrored by the fate of the Milanese state in the wake of her death, at the ripe age of 76 in 1501. Although her astute stewardship had advanced Milanese hegemony well beyond the Po Valley (even surpassing the territorial accomplishments of her grandfather, Gian Galeazzo) she was also to be the final ruler of the Visconti dynasty, earning the epithet “
the Last and the Greatest” by the scholarship of posterity.
Born out of wedlock to the Duke of Milan, Filippo Maria, and his mistress Agnese del Maino (the only woman whom the timid duke ever truly loved), Bianca Maria received an excellent humanist education, to which her mind and character were wholly suited. The duke doted on his natural daughter and gradually came to see her as a potential successor. Standing between the imposing martial figure of Gian Galeazzo and the golden age that would become the reign of Bianca Maria, modern historiography has always tended to portray Filippo Maria as an intermediary figure. However, without his decisive defeat of the Venetians in 1452, it is unlikely he would have gathered enough political capital to force through the elevation of his legitimised daughter to the line of succession. Indeed, the victory came none too soon. Three years later, the duke was dead.
In the confusion of 1455, Bianca Maria moved swiftly to outmanoeuvre her opponents. Beguiling the important condottiero Francesco Sforza into supporting her hand in marriage, the duchess seized the apparatus of state ahead of a nascent republican movement. When Sforza tried to force through the marriage, Bianca turned on him, had the general imprisoned and eventually executed. Over the next four decades, she ruled with “...
the magnanimity of Augustus and the ruthlessness of Livia.” By aligning with the emperor, she garnered considerable authority on the Padan Plain, which she employed in bringing the Ligurian coast under her control in 1461. Five years later, the Venetians attempted to regain their losses in Lombardy, but was once again defeated by Milanese forces led by the brilliant “tourney captain” Andrea d'Alviano and the Piccinino brothers. With an incredible political sense, the Great Duchess subsequently expanded her domains across the length and breadth of Northern Italy, culminating with the submission of the Florentine Republic only a few short months before her death in early 1501.
Matrimony played an important part in renaissance politics and Bianca Maria would be wed and widowed thrice. However, her only son, Ercole, predeceased her in 1492, ostensibly of the plague, although contemporary sources indicate that he might have been poisoned by a cabale of Sforza supporters. As such, Bianca Maria’s death left the Duchy of Milan without a clear successor. As enemies of the state began to creep out of the woodwork, republican garrison commanders, university rectors and guild masters in the city of Milan acted decisively to prevent the imposition of a foreign prince. On Christmas Day 1501, the Archbishop of Milan, Giovannangelo Arcimboldi, proclaimed the establishment of the Golden Ambrosian Republic. For the next four years, the republican government did its best to fight off the League of Pesaro, a coalition of dispossessed princes and revanchist foreign powers led by the Papacy. At the forefront of the Milanese war effort was the condottiero, Allesandro Doria. The scion of an ancient Ligurian noble family, Doria decisively defeated the League navies off Corsica in 1505, bringing the war to a victorious end. His status as a war hero and a champion of the provinces propelled Allessandro to the top of the Ambrosian Republic, a position he exploited to the full when he abrogated the constitution and made himself Duke of Milan in 1507.