Paul Callaghan was 27 when he entered the third series of The Apprentice.
Like fellow Apprentice candidate Katie Hopkins, Paul Callaghan attended the Sandhurst Royal Military Academy. The two became close in The Apprentice and, in programme 3, Tre described Paul as like a puppy dog following Katie around all the time.
In week 6 of The Apprentice, Paul Callaghan's closeness to Katie Hopkins was brought up in the boardroom, but it was just one contributing factor to make Sir Alan Sugar say: "I'm, very disappointed. I had more in mind for you ... you're a total shambles. You're fired!"
After graduating, Paul Callaghan became an HR and Resource Manager for the Army.
He was posted to Iraq as Infantry Commander and spent six months serving in Basra.
The ex-Army Lieutenant has a BSc in Engineering Physics and heralds from Southampton.
Paul Callaghan's first job was selling jumpers on his parents market stall in Brussels. He was also a trainee building surveyor.
Paul Callaghan's hobbies include sky diving, polo, and yachting.