The Eye in FBI

Bobby Manning was born in Australia in the early 70s⁽¹⁾ to an American father - Mac Ellis - and an Australian mother. When he was six, his father left without a forwarding address and it was only years later that Bobby got to reconnect with his absentee father. His mother remarried and her new husband adopted Bobby (hence the name Manning)⁽²⁾. For all intent and purpose, Bobby considers this new man in his life to be much more of a father to him than Mac ever was.

Bobby is a skilled explosives expert. Before joining the Bureau, he was on a SWAT team (where was never said on the show) for a number of years. He joined the FBI Academy at the same time as Jack Hudson and the two struck a friendship that has lasted throughout the years. It's that friendship that helped Bobby get over a bad gambling habit early on in his career.

While his romantic past before the series remained unexplored, it seems that Bobby has a knack for getting himself into complicated relationships first with ace-reporter Darcy D'Angelo and later on with coworker Tara Williams...

1. This is an estimation only and not something set in stone.
2. It is also possible though unlikely in my book that Manning is his mother's maiden name...