Have you ever heard of the Battle of Agincourt? Until recently, I only vaguely knew about it. After learning more, I see that fight as an incredible example of leadership that’s as inspiring today as it was in 1415.

The battle was part of the Hundred Years’ War between England and France, and the English side, led by Henry V, was in bad trouble. Not only were their forces outnumbered by at least 5 to 1, the men were hungry, tired and suffering from dysentery. Conversely, the French had a large number of fresh, armored knights and horses supported by archers.

The moments before the battle were brilliantly depicted by Shakespeare in his play, Henry V, and, while there’s no way of knowing this, I choose to believe that it was Henry’s speech to his depressed, frightened soldiers that created conditions for England to pull off its amazing win.

Through a stunning display of leadership, Henry grabs his men’s psyches and yanks them up from despair to near euphoria. By the time the battle begins, rather than being terrified, the outnumbered soldiers are eager to fight, knowing they will make history in a story that “the good man [shall] teach his son … from this day to the ending of the world.”

But it’s not just the speech that I find so inspiring. It’s also the tactics used to accomplish the win — tactics that can be developed in business even today.

For starters, Henry fought alongside his men in hand-to-hand combat, always on the front lines, always ready to risk his life for his “band of brothers.” Similarly, when a business owner rolls up his or her sleeves to help with a task, rather than handing it off to an overworked staff, the company’s employees will respond by trying that much harder. It’s no coincidence that King Charles VI did not command the French army that day.

In addition, even though England had enormous disadvantages, Henry ordered his forces to attack first. While he made the choice for a number of reasons, the element of surprise was a big part of the strategy and it worked to put France off its game from the very beginning of the battle. Remaining nimble, aggressive and unpredictable is a huge part of success in business just as in war.

Finally, Henry turned the French cavalry to his own advantage. Waiting until the horses were in range, he wounded them in the flanks with arrows, making the terrified animals wheel and gallop backwards directly into the infantry behind them. This gift of turning an army’s strength into a liability can be seen today in many effective marketing campaigns where a company creates the perception that its competitor is too large to provide good customer service.

Somehow, I managed to get through nearly 50 years of life without knowing very much about Agincourt. I’m glad I had the chance to learn.