The Borromeo family originated from San Miniato in Tuscany but were forced to leave central Italy (1370) when they were exiled, and Filippo, who in 1367 had lead the town's uprising against Florence, was condemned to death.

Once they had moved to north Italy, thanks to the various branches of the family, and to its real estate and equity interests in the banks of central-north Italy, the Borromeo family were soon present on all the most important European financial markets.

Vitaliano I (circa 1391-1449) was the founder of the lasting fortune of the Borromeo family in Lombardy. He had a very important financial role and notable political weight in the court of the Visconti family, accumulating a large fortune thanks to his sharp mind and business flair. He was also responsible for the initial purchase of land in the northern Novarese area near Lake Maggiore (1439/1447), which formed the first nucleus of what was to become the Borromeo State.

Under Giberto I (circa 1460 -1508) and his brother Lancillotto (1473-1513) there was a decline in the political and military role of the family in Milanese affairs. Thereafter, the family's aristocratic vocation prevailed and their merchant capital was progressively converted into landed income. This was also the period in which the first purchases of land on the islands in the Verbano region were made, and the fortified settlements were in part, transformed into country residences. Under Giberto II (circa 1511-1558), feudal power was united to religious power thus marking, in a lasting manner, the family's image and history.

Carlo Borromeo (1538-1584), who had been destined since birth to an ecclesiastical career, quickly reached the highest levels of the Church hierarchy. He was appointed archbishop in 1564, and in 1566 in Milan, he began a widespread reformation of the diocese, reorganising its structure and promoting the role of the clergy and of the parishes. At the time of his death, Carlo Borromeo was a hugely popular figure.

His cousin Federico (1564-1631) resolutely sustained the process of canonization that ended with the solemn proclamation of the sanctity of Carlo Borromeo in Rome, on 1st November 1610. The Cardinal's predilection for philosophical and literary studies led him to set up the Biblioteca Ambrosiana (Ambrosiana Library - 1607), one of the leading cultural institutions in Europe at the beginning of the seventeenth century. This was later followed by the Pinacoteca (Picture Gallery - 1618), and the Accademia del Disegno (The Academy of Design - 1620). He was also responsible for establishing the Sacro Monte di Varese.

Under Carlo III (1586-1652), nephew and heir of Cardinal Federico, the power of the ancient dynasty was maintained in the context of the process of the "Hispanicization" of the ruling classes in Lombardy, and thanks to his three children, the family began a new and glorious phase of its history.

Nowadays, the family’s history is characterised by its cultural interests, which far outnumber its political interests, and it is engaged, with uncommon sensitivity, in the preservation of its considerable historical and artistic heritage.