In the 16th century, when the Italian peninsula exploded with clashes between the Imperials, the French, and the Duchy of Milan, Gian Giacomo Medici (1498–1555) seized both opportunity and necessity. Driven by personal upheaval and seeking to carve out power and security amid the chaos, he exploited the instability to establish his own state on Lake Como.

Son of Bernardino Medici—a Milanese nobleman unrelated to the wealthier and more powerful Florentine Medici—Gian Giacomo grew up in Milan amid typical Renaissance noble distractions. His exuberance led him, at 16, to commit murder and flee Milan to avoid punishment. He found refuge in Como, on the lake's picturesque shores and in its villages.

Here, between 1520 and 1521, while northern Italy was a battleground between the French, the Imperials of Charles V, and the Sforzas, Medeghino—as everyone called him—seized Musso Castle, a hill directly overlooking the lake. He was motivated by both the strategic advantage this stronghold offered and the chance to assert control over his environment. Exploiting his military skill and violent temperament, Gian Giacomo transformed the castle into a formidable fortress from which he intended to dominate the bay below his residence, fueled by the ambition to secure autonomy and influence.

With his remaining money, he equipped a small fleet of mercenaries, whose boats could control the lake and, on land, levy taxes on merchants and local inhabitants, as well as carry out ambushes by exploiting the topography of the surrounding Como territory. In 1528, Gian Giancomo Medici even minted his own coin to be used in the territories adjacent to his fortress, as if it were the capital of his own personal state. This attracted the attention of the imperials, particularly Charles V's governor, Antonio de Leyva. Unable to defeat Meneghino in a territory so unsuitable for large-scale military manoeuvres, he decided to buy his castle in exchange for the title of Marquis of Musso and Count of Lecco.

The Medici destroyed the castle and surrendered his arms to the empire, but he emerged from humble beginnings with wealth, fame, and a title he could now claim.