The Elizabeth star spoke recently about having her kids on set during the filming of her new movie.
Her young son dressed up as a knight and protected her on the set of her latest movie.
She said that her five-year-old son was so obsessed with knights the assistant director kindly let him play the part off screen.
Cate revealed to Bang Showbiz, "It was fantastic to have the kids on set.
Dash, my eldest, who was then not quite five, was into knights at the time and his godmother had given him a plastic knight outfit.
"Tommy Gormley kindly said he could stand and protect me. So in the scene where Clive Owen is talking about the immensities and I'm sitting on the throne, I'm actually looking through an archway at my son standing in a knight's costume protecting me.
"He stood for like five minutes and each take was different for him. He was a natural, unfortunately."