The youngest of Grand Duke Henri’s and Grand Duchess Maria-Teresa’s five children, Sébastien, 25, was sworn in at Berg castle in Colmar Berg on Monday, 4 September 2017.

On 11 August, the young prince graduated from the Royal Military Academy in Sandhurst, UK, in a ceremony that was attended by his parents.

Prior to his training at Sandhurst, Prince Sébastien graduated with a degree in marketing and communications at the Franciscan University of Steubenville in 2015.