From an interview of Steven Ballmer in the New York Times:
Q. If you could teach any b-school course, including one that you create, what would it be?
A. Leadership. Microsoft has grown from 30 people to more than 90,000 since I started, so I’ve had the chance to play a leadership role at practically every stage imaginable in a company’s growth and development. I’ve learned a lot about leadership along the way from some great people that I’ve worked with and through experience.
I’ve come to believe that to be a great leader, you have to combine thought leadership, business leadership and great people management. I think most people tend to focus more on one of those three. I used to think it was all about thought leadership. Some people think it’s all about your ability to manage people. But the truth is, great leaders have to have a mix of those things.