Prior to this, he left his mentor Batman, in an effort to make it on their own as crime-fighters.
As elaborated upon in the 'Go' episode, Robin forms the group after aiding Starfire in her escape from captivity, with the help of Beast Boy, Cyborg, and Raven.
Although he is the only one of the group without any superpowers, by virtue of his heroic experience and reputation, Robin is the fierce but highly disciplined leader of the Teen Titans.
