Peter Drucker, one of the best known thinkers and writers of our day had this to say about leadership:
"You know, I was the first one to talk about leadership 50 years ago, but there is too much talk, too much emphasis on it today and not enough on effectiveness. The only thing you can say about a leader is that a leader is somebody who has followers. The most charismatic leaders of the last century were called Hitler, Stalin, Mao and Mussolini. They were mis-leaders! Charismatic leadership by itself certainly is greatly overstated. Look, one of the most effective American presidents of the last 100 years was Harry Truman. He didn't have an ounce of charisma. Truman was as bland as a dead mackerel. Everybody who worked for him worshiped him because he was absolutely trustworthy. If Truman said no, it was no, and if he said yes, it was yes. And he didn't say no to one person and yes to the next one on the same issue. The other effective president of the last 100 years was Ronald Reagan. His great strength was not charisma, as is commonly thought, but that he knew exactly what he could do and what he could not do."
To read the rest of what he had to say, go here - I highly recommend reading this!