Why Prince Mateen and Danial Deen Isa-Kalebic are raising the bar for the gentleman persona in 2025

Danial Deen Isa-Kalebic and Prince Mateen.

Photo: Instagram/princemarteenfan

The modern nobleman isn’t just about lineage; he’s about legacy. Prince Mateen, the son of the Sultan of Brunei, and Danial Deen-Isa Kalebic, the grandson of Pehin Dato Awang Isa, a special advisor to the Sultan of Brunei, both come from noble backgrounds that emphasize excellence in education, elegance, and etiquette. Both gents graduated from King’s College London, one of the finest institutions in the world. Both have cultivated a level of education that allows them to navigate global diplomacy, high society, and elite business circles with the effortless ease of a Bond protagonist ordering a martini.

Fitness Fit for Royalty

Danial Deen competed in his first Hyrox in Hong Kong.

Photo credit: @danialik/Instagram

A man of nobility isn’t just defined by his mind—his physique is just as important. Both Prince Mateen and Danial Deen exude a commanding presence, thanks in part to their rigorous commitment to fitness. Prince Mateen is a trained military officer, having completed rigorous training at the Royal Military Academy Sandhurst. His Instagram, a visual portfolio of his polo-playing, gym-sculpted physique, and adventurous lifestyle, has made him an icon of modern masculinity. Meanwhile, Danial Deen follows a disciplined fitness regimen that keeps him looking like he could walk straight off a Milanese fashion runway onto a battlefield, should the need arise. The takeaway? Nobility is not just a title; it’s a discipline—one that requires strength, endurance, and the ability to make a tuxedo look like battle armor.

Cultural Sophistication

Prince Mateen and his wife, YM Anisha Isa-Kalebic celebrating their 1-year wedding anniversary in Florence, Italy.

Photo credit: @tmski/Instagram

Beyond their striking appearances, both gentlemen exhibit a deep appreciation for art, culture, and global traditions. Prince Mateen, fluent in several languages, seamlessly blends his Bruneian & Japanese heritage with a cosmopolitan worldview, attending international events with the grace of a seasoned statesman. Danial Deen, meanwhile, epitomizes the true Renaissance man—his appreciation for the nature's beauty, slow living, and fine tailoring signals a depth of cultural knowledge that extends beyond mere social appearances. These men aren’t just showing up at events; they are the event.

The Gentlemanly Style Playbook

Prince Mateen and his wife, YAM Pengiran Anak Isteri Anisha Rosnah celebrating their 1-year wedding anniversary in London.

Photo credit: @tmski/Instagram

Prince Mateen and Danial Deen have cracked the code for modern nobility’s dress code: understated but commanding. Prince Mateen’s wardrobe is a masterclass in regal minimalism—sharp suits, military uniforms that exude authority, and casual ensembles that say, “masculinity elegance”. Danial Deen, on the other hand, embodies European sophistication, blending classic tailoring with modern cuts that make him look like he’s perpetually ready to step onto the set of a high-end fashion editorial. If there’s one lesson to take from them, it’s that a true gentleman never overdresses; he simply is well-dressed.

Danial Deen Isa-Kalebic and Janetira Attaskulchai-Deen in Spencer House, London.

Photo credit: @janetira/Instagram.

A Lesson in Nobility for the Modern Gentleman

So, what can the aspiring gentleman learn from these two modern noblemen? First, that education is the foundation of true sophistication. Second, that fitness is not about vanity but about self-respect and discipline. Third, that cultural exposure is about understanding beauty in a way that allows you to grow in soul and intellect. Finally, style isn’t just about what you wear, but how you carry yourself.

Prince Mateen and Danial Deen Isa-Kalebic aren’t just redefining modern nobility—they are proving that elegance, intellect, and discipline never go out of style. And for the rest of us mere mortals? Well, let’s just say it’s time to step up our game.