No. 1: Dick Grayson - The First Robin
Created by Bob Kane, Bill Finger and illustrator Jerry Robinson he first appeared in Detective Comics #38 in April 1940. Dick Grayson was a circus performer for Haley’s Circus along with his Mother and Father, they were The Flying Graysons. As mobster Tony Zucco tried to intimidate Mr. Haley into giving him protection money, he sabotaged the lines on the trapeze knowing that performers did tricks without the safety of a net.
Bruce Wayne was in attendance at the circus that night, as he, Dick and the rest of the audience watched Mary and John Grayson plummet to their death. Bruce took Dick Grayson in as his ward and eventually revealed to him all the hidden secrets of Batman. Dick wanted to help out and eventually came up with the Robin costume. Depending on which version of the character you are reading or watching, the exact path from ward to Robin differs, but the circus show is always an integral part.
Dick is an amazing acrobat and is typically depicted as generally happy-go-lucky guy. Some of his characteristics may be based on the era he was created in, some might be based on the 1966 Batman TV series. Along with being a character created for younger readers, Robin was also there to bring a little levity to the Batman series.