Prince Harry is a trained military combatant, retiring from duty in 2015 after 10 years of service.
Despite his training, he won't always be with future-wife to protect her. That's why the actress will undergo military training from the British Special Air Service, which is standard for royals-to-be.
Kate and Diana underwent the same training, which focuses on how to deal with a hostage situation. According to Scott Jones, director of a security firm in London, the training will last about a week. It will train her how to deliver distress signals if she's held hostage and is forced to record a video. These signals include keywords, micro-expressions, and other behaviors to signify to law enforcement that she is in distress. Markle will also learn some basic psychological techniques to deal with potential captors.
A source from the British Armed Forces says the training won't involve weapons or combat, and will primarily be focused on "facilitating a rescue."
It's unclear as to when the training will take place, but it will most likely be as soon as possible.