Martens, 41, is currently creative director at Diesel and was promoted internally from within the Italian fashion company OTB Group which also owns Maison Margiela.

"I have worked with Glenn for years. I have witnessed his talent, and I know what he is capable of," the billionaire chairman and owner of OTB, Renzo Rosso, was quoted as saying in a company statement.

Rosso was instrumental in resurrecting the career of Galliano after the then drug and alcohol-addicted British designer fell into disgrace in 2011 due to an anti-Semitic rant in a Paris bar.

Galliano parted company with Maison Margiela in December after 10 successful years of rising sales, making him a hard act to follow.

Martens, who made his name at now-defunct experimental label Y/Project, studied at Antwerp's renowned Royal Academy of Fine Arts like Martin Margiela, who founded his eponymous label in 1988.

"After Martin, who gave life to the Maison and its unique Artisanal line, and John who made it the most cutting-edge couture house in the world, I am proud to have a third couturier at its helm," Rosso added, referring to Martens.

- War worries -

Elsewhere on Wednesday, Italian brand Valentino, Dutch duo Viktor & Rolf and French designer Franck Sorbier showcased their Spring/Summer 2025 collections during Haute Couture Week along with Jean-Paul Gaultier and Lebanon's Zuhair Murad.

In an increasingly unstable world, Sorbier had war and peace on his mind in a typically theatrical show that combined music, singing and dance.

Titled "Symphonie barbare" ("Barbaric Symphony"), it featured bare-chested "barbarian" men and female "warriors of peace" dressed in trapeze gowns adorned with tassels or sequins.

It ended with a "peace" phase and concluded with Sorbier appearing in a black anorak bearing the words "peace and love".

"The idea is not to get stuck in a bubble of haute couture," he told AFP. "Even though we do haute couture, we can still talk about the news and worrying issues, without sounding like we're giving lessons to people," he said.

Zuhair Murad, whose country has been under Israeli bombardment, said his glamourous collection of long evening wear was inspired by the idea of a tropical island inhabited by goddess-like women.

"The message of this collection is about escaping from our hectic world. I imagined this beautiful island, far from the cities, far from technology, far from the world that we live in right now, a peaceful world," he told AFP.

- LVMH slide -

Haute Couture Week showcases one-of-a-kind, entirely handmade pieces which are primarily intended for red carpets, high-profile events and galas.

The luxury industry as a whole is facing a slowdown linked notably to weaker-than-usual economic growth in China.

French fashion powerhouse LVMH, Europe's largest company by market value, reported Tuesday a 17-percent fall in net profit last year and a two-percent decline in sales.

The business, which owns Louis Vuitton, Dior and Kenzo among other leading brands, attributed the slide to the end of the "euphoria" of the post-Covid period.