Leaders: Myth and Reality by Stanley McChrystal, Jeff Eggers, and Jay Mangone. The team that wrote this book was obviously lead by McChrystal, and it draws heavily on his experiences. The format is paired profiles of leaders from different eras who shared a single defining characteristic or similar story. But to start off, they examine one leader alone: Robert E. Lee. They note that he'd had a mythos about him as "the Marble Man" even back to his West Point days. They discuss Lee the legend versus Lee the flawed human being, and drag right out into the open the problem with idolizing a man who was offered command of the Federal Army, but turned it down and fought to keep African-Americans in chattel slavery. A main point is that Lee the legend is different from Lee the human being. The legend was created by other people and for other people, in order to serve the psychological needs of people not named Robert E. Lee.
The pairs are interesting:
FOUNDERS: Walt Disney and Coco Chanel
GENIUSES: Albert Einstein and Leonard Bernstein
ZEALOTS: Maximilien Robespierre and Abu Musab al-Zarqawi
HEROES: Zheng He and Harriet Tubman
POWER BROKERS: Boss Tweed and Margaret Thatcher
REFORMERS: Martin Luther and Martin Luther King, Jr.
They then wrap up with a discussion on a higher level, with some excellent points about how human beings misunderstand how and why we pick leaders, and what makes them effective. First, it's highly situational. Just because you're successful in one environment, with one group of people, doesn't mean that there's some grand principle of leadership that can be distilled down for everyone to use. Second, leaders don't have as much power as they think they do. This is a common theme of McChrystal's writings. Powerful people can't issue diktats from on high; they have to create a culture for other people to thrive in. Ultimately, power and influence are not things you can seize. They are things given to you by other people, and they can vanish in a heartbeat. Third, leaders emerge as much because people want them to as because of the efforts of the leader themselves. The actual human being becomes the focus of the psychological needs of his or her followers, and this is why people get mythologized. It's also why the Elon Musks of the world can grind people the way they do - people will go to the mat for a cause they believe in, at least for a short while.
An example they bring up towards the end of the book is Churchill's failure to be elected PM after leading the country through WWII. He was a legendary leader for that time. Then times changed. A telling anecdote they bring up is Churchill having his official portrait painted post-WWII. He and his wife hated it, and when it was shipped to his home, his wife had it burned. Perhaps that was because the painter didn't paint an idolized portrait of Churchill the legend, just one of a mortal man towards the end of his years.