The original Robin, and future Batman for a time, Dick Grayson had a destiny the moment Bruce took him in as his ward.
Dick was part of a circus of great renown, his family was known as the Flying Graysons, and he was a young prodigy in the making. But when a gangster called Tony Zucco killed his parents in an attempt to extort the circus, his life before was gone.
Though initially not taking him in to be a sidekick, Dick did eventually figure out Bruce's secret, and not long after became Robin. Depending on which continuity you believe, they had a long partnership, but as time went on, Dick wanted to spread his wings and fly on his own. So he left Gotham, adopted the title of Nightwing, and defended Bludhaven for a time.
But fate would eventually bring him back to Gotham, and numerous times did he don the Batman cowl. Grayson has led many teams, and has proven time and time again to be one of the most skilled non-powered heroes in the DC Universe. He is often thought of as the greatest Robin, and with good reason.