Founded the dynasty's fortunes by expanding his father Giovanni di Bicci's financial empire to become personal banker to various European kings and, crucially, the papal curia in Rome while also making himself an indispensable advisor to the city council. Nicknamed "Father of his Country."
Cosimo il Vecchio orchestrated a number of important alliances and treaties for the Florentine Signoria, gaining him prestige and respect.
Though wary enemies like the Albizzi feared Cosimo’s growing power—even though he rarely held any official office—and got him imprisoned and then exiled in 1341, he was soon recalled by the Florentine people.
As Cosimo il Vecchio’s behind-the-scenes power grew, he made sure to remain almost always a private citizen and businessman, serving the needs and interests of the working and middle class without needlessly overangering the big fish in town. While his position also helped him increase his personal fortune, he took care to spend lavishly on the city, building churches, establishing charities, and patronizing artists.
Cosimo was a humanist leader who believed in the power of the emerging new art forms of the early Renaissance, and he commissioned works from the greatest painters, sculptors, and architects of the day.
Cosimo grew so attached to the sculptor Donatello that, as Cosimo lay dying, he made sure his son, Piero the Gouty, promised to care for the also aging artist and to see that he never lacked for work.
Cosimo, as a properly modest ruler, was so beloved by the people that they buried him under the inscription Pater Patirae — Father of the Homeland.
(When Donatello himself later died, they buried him nearby.)