Accession to the throne | The monogram of the future Grand Duke Guillaume

The Maison du Grand-Duc is honoured to present the official monogram of the future Grand Duke Guillaume, which will be used formally from 3 October 2025.

The monogram, consisting of two symmetrical letters ‘G’ mirroring each other and surmounted by a crown, will appear on the uniforms of the Army, the Police, the Prison Service, Customs and Excise and the CGDIS and will serve as the official symbol of the future Grand Duke.

The creation of this new monogram is based on a historical analysis. Four cases were identified:

• double first names with symmetrical initials (Marie-Adélaïde),
• single first names with non-symmetrical initials (Jean),
• single first names with symmetrical initials (Henri) and,
• as an exception, single first names with two non-symmetrical letters, ‘C’ and lowercase ‘h’ (Charlotte).

A symmetrical letter is a letter whose reflection in a mirror remains unchanged. Several capital letters have this property in relation to the vertical axis: A, H, I, M, O, T, U, V, W, X, Y. C, J and G are non-symmetrical letters.

While purely graphic additions were incorporated into the monograms for Marie-Adélaïde, Charlotte and Jean, there was no such need for the monogram for Henri.

The Maison du Grand-Duc called upon Luxembourg graphic designer Yolande Kaiser (yo.ko.graphics) to stylise the G of the future Grand Duke, thus reviving the tradition of non-symmetrical mirror letters.

'Prince Guillaume opted for a G style inspired by italic handwriting, ’ explains Yolande Kaiser. ‘Based on this calligraphic orientation, several sketches were developed, taking into account both practical considerations – such as the use of the monogram as a badge on uniforms – and the specific wishes of Prince Guillaume and Princess Stéphanie. One of the key elements for the Prince was that the letter “G” should be immediately recognisable.

To enhance this feature, elements of the letter's curve were incorporated inside the monogram, adding a decorative and airy touch. Designed according to the principles of the golden ratio, the monogram subtly widens upward towards the crown. The outer edges of the crown and the double G are perfectly aligned, reflecting a concern for geometric harmony.

The crown itself has been redesigned for the occasion, faithfully respecting the official crown of the Grand Ducal Court. For the insignia intended for uniforms, the crown rests on top of the G.'

The monogram is accompanied by a complete graphic charter. Any reproduction of the monogram is subject to prior authorisation from the Maison du Grand-Duc.