What Makes a Great Leader? Editor-in-chief Amy Cosper on the many aspects of leadership.

Alexander the Great persevered against all odds. He conquered cities and entire regions deftly, with a shrewd genius that still baffles military experts. So cunning was his strategy, in fact, that on certain occasions he simply showed up, threw down his flag and proclaimed the chosen territory "Alexandria." With his troops always near, Alexander changed the borders of Egypt, Asia and Persia by uniting different ethnicities and fusing tribal customs. And in so doing, he changed the culture of the ancient world and laid the foundation for the region today.

History is a powerful teacher and one that comes with plenty of business lessons--from both heroic leaders and failed ones. Alexander was a hero and a warrior, yes, but first and foremost, he was a leader. He inspired, rewarded and acknowledged those who fought alongside him. He instilled confidence and trust. His soldiers were willing to follow him anywhere.

Great leaders do many things, but perhaps their most telling characteristic is a natural and authentic ability to inspire excellence while maintaining strength and a modicum of humility. These are the people who will lead you to success--in the battlefield or in the boardroom. The true reflection of a leader's ability is measured not only in a company's bottom line, but also in the success and empowerment of each individual.

Being a boss doesn't necessarily make you a leader, nor does being bossy. In fact, a leader isn't always the boss. The difference between the two is this: Bosses manage; leaders inspire. Anyone can manage, but not everyone can lead.

Great leaders command confidence and trust not by demanding, but by encouraging. Even in the face of defeat, a great leader will tell you to get up and keep fighting. And more often than not, failure is part of the equation. That's OK, because great leaders know when to admit their missteps and have an equal willingness to learn from them.

Theories about effective leadership ebb and flow with the times. Right now we seem to be somewhere between the "mindful" leader and the very touchy-feely "collaborative" leader. These trends don't just happen willy-nilly. As we demonstrate in our story here, today's best leaders are those who, either through effort or subconsciously, adapt their styles to resonate most effectively with the needs and personalities of their companies and teams. These leaders are embracing and encouraging change--changing business models, changing economies and, most of all, the changing labor pool. And in the process, they are revolutionizing today's business culture.

Amy C. Cosper,
Editor in chief
Follow me on Twitter, @EntMagazineAmy