Leadership is some of the hero's powers. If you have a good Leadership, y
Leadership boots

The extra effect (with the crown) you can see at the right-down corner, is (bonus) leadership.

our Morale will refill faster in battle. You can get it from items in the Item shop, and leveling up your hero. Normally the Cape and the Helmet give you extra Leadership, but you can get it as an extra on your (example) boots too.