The Duchess shared photos from her visit last November to Pirbright Army Training Centre and Abingdon airfield in honour of Armed Forces Day on June 25. The annual event honours and commemorates all personnel who make up the British Armed Forces, including their families and cadets.
Kate shared the photographs on the official Instagram page for the Duke and Duchess of Cambridge.
She said: “Today on Armed Forces Day, William and I would like to pay tribute to the brave men and women, past and present, serving in all of our armed forces, at sea, on land and in the air here in the UK and around the world.
“Thank you for all you and your families sacrifice to keep us safe.”
She added: “Last year, I was honoured to spend time with the British Army to see how they train serving personnel and new recruits.
“It was wonderful to see first-hand the many important and varied roles in the military play day in, day out to protect us all, and I look forward to discovering more about the Royal Navy and Royal Air Force in due course.”
The series of pictures featured the Duchess wearing army combat gear while she was learning about different military equipment and partaking in some of the training exercises.
She was also pictured smiling at the camera with a helmet on as she moved the attached microphone to her mouth.
One fan using the username @Kelowna74 commented on the post: “Fantastic, so much enthusiasm from Catherine.
“She a real credit to the UK, Royal Family and the monarchy.”
The account added in another comment: “This picture depicts what real royalty is like!”
Another royal supporter said: “What a great surprise to mark #ArmedForcesDay!
“I love it and the fact that you visited the Brigade months ago and we had no idea about it!
“You and your husband do so much behind the scenes.
“I’m sure the soldiers you met on that day will treasure this moment forever.”