Background History[]
Dick Grayson's career as Robin begun at the age of 9
Richard "Dick" Grayson was the child of the acrobatic circus family "The Flying Graysons" of Haly's Circus. He was named after his uncle, Rick. His parents John and Mary, along with his older cousin John and aunt Karla fell to their deaths in a trapeze "accident" caused by mob boss Zucco on April 1st, 2006 when he was 9. The only survivor other than Dick, who did not participate in the fatal routine, was his uncle Rick, who was very badly injured and unable to care for him. Richard has since lived with Bruce Wayne and made the transformation to Robin under Bruce's training (eventually bringing Zucco to justice together). Batman's main motivation was to make sure young Dick would not grow the way he did with vengence and revenge.
During his time as Robin, Dick trained hard to master his acrobatics and eventually developed a expertise in impressive martial arts, marksmanship and detetive skills at the age of only 10. During this time he also trained alongside Barbara Gordon who was Batgirl at the time and the two become close friends and a cohesive unit alongside Batman.
Robin continued to grow as a hero during his teenage years
Several years later, at the age of 13, Robin also met other young sidekicks including his close friends Aqualad, Kid Flash and Speedy and formed the Teen Titans while remaining Batman's protege. Robin developed a nact for leadership and was more experienced then the other sidekicks but struggled to develop a Team until he decided to step down from leadership until he was truely ready.
During these years Robin began to develop a conflicting personality with that of Batman due to his priority of his team mates rather then whatever is at stake. Batman also continued to treat Robin as a kid despite he was growing into a very capable superhero during only his teenage years. Robin began to drift more and more away from Batman due to their issues but eventually disbanded the Titans and returned to Batman's side, only to make matters worse. Soon after, Barbara Gordon was shot and paralyzed by the Joker traumatizing Robin. Robin blamed Batman for this due to his sense of urgency for "the mission" instead of protecting Batgirl while Robin was away. Dick then decided to quit the role of Batman's side kick the Boy Wonder.
Nightwing became his own hero after leaving Batman's side
Dick left Gotham to travel the world and exposed himself to the many people he wanted to protect by becoming stronger independently. During this time he ventured to Metropolis and was mentored by Superman who inspired him to become his own man and not that of Batman. He returned to Gotham and decided to show Batman that theirs another way to be a "hero" and invented himself into the superhero "Nightwing", named after one of Superman's past kryptonian friends.
The two looked over Gotham as more rivals then parteners due to Nightwing's anger towards Batman over Bruce's morality. Eventually Nightwing decided to leave Gotham in Batman's capable hands and soon became the Guardian of Blüdhaven which intern led him to come to terms with Batman after realizing how tough it is to bring a city in darkness to the light. Nightwing then began to reconnect with both Batman and his old allies in order to reform the Titans. It now works as a covert team to work under the Justice League, due to his great heroism Nightwing was invited into the League but refused and instead became the leader of the Titans in Aqualad's place.