As Princess Diana’s bodyguard, Ken Wharfe had his share of tough days protecting the late Princess of Wales. He recently told Marie Claire that she “didn’t always welcome” having a royal protection officer, but when it came to carrying out her royal duties, there was one major reason why Diana never backed out.

Wharfe, who served as Diana’s bodyguard from 1988 to 1993, shares that even when the princess didn’t want him around, she never actually refused protection. “I think possibly, on some occasions, if we’d had a difficult day the night before, she might have said, ‘Oh dear, you know, I can’t cope with this. I don’t want you today.’ But thankfully, that never happened,” he says, speaking on behalf of Casino.org.

Wharfe continued, “And I’ll tell you why I don’t think it ever would have happened. At that particular time, despite the unhappiness of her marriage, her commitment was to Her Majesty The Queen.”

He adds that even though Princess Diana’s relationship with Prince Charles was falling apart, “She was in a position where she was loyal to the workings of the British Royal Family and would never let them down, despite her personal unhappiness.”

Even on days when she’d say, “I don’t think I can do today, Ken,” Diana would soldier on and carry out her commitments. Wharfe says he’d suggest, “Well, okay, you don’t have to. What do you want to do about it? We can find a reason not to do it. You can be ill, or we can come up with some excuse.”

“But the answer would always be, ‘Well, I can’t let my mother-in-law down,’” he shares. “So there was a real sense of duty on her part.”

Wharfe stepped down from his role in 1993, and he admits that he’s not sure what would have happened if Diana had ever refused his protection. “Quite how I would have dealt with that, God knows,” he shares.