A True Hero

[Gail Allen]

After reading the Song of Ice and Fire I have been thinking about a question :What makes a character into a Hero?

In this book series I definitely think there are heroes, but unlike in many fantasy books these people aren't just good or bad, they're complex and they feel human. But then, what makes them into heroes despite that? Or are they really heroes at all or do I just perceive them as such even though they aren't?

I am really curious what makes a character a hero in your opinion.