Winston Churchill was a veritable fount of quotes and knowledge, and he was certainly the right man in the right place during World War II. Courage is the first quality because without it no growth can happen. Without the courage to take the step, there is no improvement. So yes, courage must come first, before any human endeavor.
A little background on the picture. This was the first time my oldest son and a family friend's daughter remember going to the beach (my oldest son had gone a couple times before when he was much younger, but he kept to a tide-pool and not the crashing waves of the ocean). They were both scared of the crashing waves, but eventually, together, they worked up the courage and ran into the water, splashing and playing in the surf. Which shares another lesson in courage. Courage can be easier to find in a group rather than alone. Find people to support you and help you and it will be easier to find the courage to move forward.
In the case of leadership, this may be a little different. Courage sometimes needs to come from the leader, to show the team that they can do something. Then the courage comes from conviction and self-motives. Leadership can mean having the courage to do the right thing, to show the way, so that others will have the courage to follow.
Courage, the first quality and so complicated. How will you show courage today?