Money wasn’t the only thing that enabled financier Cosimo de’ Medici  to become de facto ruler of Florence for much of the Italian Renaissance. He exemplified a special leadership skill — the ability to get diverse teams of contending bankers, merchants, and traders to collaborate effectively. How? He identified with each group’s sentiments and mindsets. With that understanding, he succeeded where others failed: He built new bridges of common purpose, resulting in a “team” that produced greater, more sustained economic, social, and cultural value for all parties — and the broader society.