Cosimo de' Medici was the first of the Medici dynasty during the Italian Renaissance. Though he only held public office for a short while, thanks to his immense wealth and effective leadership style, he became the de facto ruler of Florence.

Cosimo was loved by the people for creating a tax system that taxed the wealthy more than the middle and lower classes. Instead of lining his own pockets, the money went to public projects like the Palazzo Medici and Donatello's Judith and Holofernes. Brian Uzzi, a professor of leadership and organizational change at Northwestern's Kellogg School of Management, writes in Harvard Business Review about how Medici's leadership brought disparate groups of people together to help create cultural and artistic icons that still endure today. 

"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," Uzzi writes.

The pillar of Cosimo's success, Uzzi says, was "multivocal leadership."

"Multivocal leadership is not about gaining technical proficiency in multiple areas--Cosimo knew banking, but not trading, merchandising, or other areas of expertise, and he didn't have the time to gain even nominal proficiency in other areas," he says. "Instead, multivocal leaders identify directly or vicariously through others with the experiences, mentalities, and skills of a diverse set of people, and fluently broker communication among teammates to guide collaboration."

Below, read more about how to use Cosimo's leadership style in your own company.

Speak team members' language

"The best leaders of diverse teams can speak the multiple 'languages' of their teammates, based on their own experience and learning," Uzzi writes. He cites the example of Shane Black, the director of blockbusters like Predator and Lethal Weapon, who says directors need to communicate with actors in a way the actors value. Great films are made not by the director demanding his actors follow his every command, but rather by every team member making their part their own. A good director can communicate how to do so efficiently and respectfully.

"Multivocal directors get the best performance out of actors by leveraging the psychology of acting in communications. They help actors understand the full context of a given scene and to evoke emotion by connecting the role with the actor's personal experience and empathizing with their frustration over multiple takes," Uzzi writes. "The same approach enables the leader to more effectively broker exchanges among teammates themselves, too."

Know what drives your employees

You need to be interested in what motivates your employees. Get to know what makes them tick and use it to help them perform. "Multivocal leaders are genuinely interested in what drives those around them," Uzzi says. "That curiosity embraces diverse experiences and yields practical knowledge about what motivates others, and what will help them to trust you." 

Be aware of your weaknesses

To be successful, you need "an almost painful self-awareness of [your] strengths and weaknesses," Uzzi writes. "Effective leaders of diverse groups understand what they themselves bring to the table, as well as the potential limits of their capabilities. That helps them to defer to the expertise of their teammates, where needed." Putting together a team with people with different strengths, you need to bring order and align the employees into a working whole. "The whole is much greater than the sum of individual contributions," Uzzi says.