The Golden Ambrosian Republic is a short-lived government founded in Milan by members of the University of Pavia with popular support.

With the aid of Francesco Sforza they hod out against the forces of Venice, but after a betrayal Sforza defects and captures Milan to become Duke himself, abolishing the Republic Sforza remains at war with Venice for years after the downfall of the Ambrosian Republic.

Venice allies herself with the kingdom of Naples, previously a contender for the succession of Milan.

Sforza, however, allies himself with his friend, Cosimo de' Medici of Florence against Venice and Aragonese Naples.

The continued war is finally closed by the peace of Lodi in 1454 with the House of Sforza as the established rulers of the Duchy of Milan.