Prince Gabriel of Belgium, the second child of King Philippe and Queen Mathilde, turned 23 on August 20th. It's a milestone that arrives as the young royal, second in line to the throne, completes four years of military training and begins to carve out a public role of his own.
A birthday on the glaciers
© WireImageTo mark the occasion, the royal family skipped the usual formal portrait and instead released photos from Gabriel's summer vacation — one that had nothing to do with palace protocol. The images show the prince, kitted out in a helmet, sports sunglasses, ropes, gloves, ice axe and crampons, working his way across the glaciers and peaks of the Mont Blanc massif, all the way to the Refuge Albert I — a mountain hut named for Belgium's third king, who was also a passionate alpinist.
"After sporting holidays that took him across glaciers and Mont-Blanc peaks, including Albert I Refuge — named after the third Belgian King, who was an alpinism enthusiast — the Prince is ready to fully enter his 24th year!" reads the Instagram post's caption. The rigorous physical conditioning of his military training doubled nicely as preparation for scaling one of Europe's most demanding peaks.
Stepping into the spotlight, solo
The mountaineering reveal caps a year in which Gabriel has quietly taken on more of the public-facing duties expected of a working royal. In May 2026, he presided over the prestigious Queen Elisabeth Competition on his own for the first time, while his parents were across the Atlantic attending his older sister Princess Elisabeth's graduation from Harvard's Kennedy School.
Weeks later, when Emperor Naruhito and Empress Masako of Japan arrived in Belgium for a state visit, Gabriel and his three siblings joined King Philippe and Queen Mathilde to welcome the imperial couple at the Royal Castle of Ciergnon.
Four years, an officer's oath, and a master's degree still to come
© AFP via Getty ImagesThe backbone of Gabriel's twenties so far has been the barracks, not the ballroom. Since 2022, he has been enrolled at Belgium's Royal Military Academy in Brussels. As part of an Erasmus exchange at France's Académie Militaire de Saint-Cyr Coëtquidan, in Guer, Gabriel earned his parachutist wings at the elite airborne school in Pau. In June 2025, he traveled to French Guiana for a grueling stint at the Equatorial Forest Training Center, where he and seven fellow cadets trained in jungle survival and combat techniques under punishing tropical conditions.
That training culminated in his commissioning as an officer on October 1, 2025, when he was sworn in before King Philippe with the rank of sub-lieutenant after completing his bachelor's degree. Then, at this year's National Day celebrations on July 21, Gabriel appeared in military uniform at the Te Deum Mass for the first time, wearing the Grand Cordon of the Order of Leopold, Belgium's highest honor, traditionally bestowed on the sovereign's children.
His formal graduation is still a week away: Gabriel is set to receive his master's degree in social and military sciences from the Royal Military Academy on August 27, closing out a significant chapter that began four years ago.
A first for the Belgian monarchy?
© WireImageWhat comes next could make Gabriel a genuine trailblazer within his own family.
In May 2026, Belgium's Council of Ministers approved a legal reform allowing royals who do not receive a state allowance to pursue paid professional careers within the armed forces. It's a change that appears to be tailor-made for Gabriel, who, as a non-heir, receives no personal dotation. Should he take that path, Gabriel would become the first member of the Belgian royal family to build a salaried career in the military, trading ceremonial duty for an active-service role in uniform.
