Mark Billingham (Billy) spent 27 years in the SAS, fought in Iraq and won the Queen's Commendation for Bravery after capturing an IRA sniper by using himself as bait. But his toughest gig was not on the battlefield - it was guarding estranged Hollywood couple Brad Pitt and Angelina Jolie.

Brad Pitt and Angelina Jolie's former bodyguard, Mark Billingham, recently opened up about his years protecting the high-profile couple. The former SAS soldier, who considered being a celebrity bodyguard his toughest job, revealed that Jolie and Pitt were worried about their children being kidnapped.

The couple was 'very worried about who goes near their children' throughout Mr Billingham's (Billy) nearly 18 months as their security ace.

Mr Billingham (Billy) said Pitt, 52, and Jolie, 41, trusted him with the children so much that as he bonded with them, he 'could take the kids anywhere I wanted to on my own.'

He also said that the former power couple were constantly uneasy about who would go near their children, to the point that they were mindful of security professionals. Mr Billingham spent so much time around the children, he said he felt like he 'fathered them, basically.'

Billy reveals he was more worried about people attacking Brad than Angelina, saying: "People love her but hate him.

"You have to figure out a way of protecting them from all that. It was challenging, but interesting." Protecting celebrities from crazed fans requires careful planning, but Billy found he also had to protect their image too, even carrying spare clothes for his charges in case theirs got stained or crumpled.

He says: "It's not so much about the physical side, but more about the social side. "I had to make sure their image was protected, that they were dressed properly and not doing silly things that could be caught on camera." Report also says that Divorce was the result of differences in parenting their children

The task was harder than it sounds, according to Billy, who says Brad and Angelina lacked some very basic social skills. Although Billy's tenure with the Mr and Mrs Smith co-stars has ended, Jolie and Pitt's ex-bodyguard admitted their divorce news shocked him.