Khalid Al Qasimi on the catwalkQasimi show, Runway, Spring Summer 2019, London Fashion Week Men's, UK - 09 Jun 2018

LONDON — Fashion designer Khalid Al Qasimi, born Sheikh Khalid bin Sultan Al Qasim, passed away in London on Monday at the age of 39.

Qasimi moved to the U.K. at nine and graduated from Central Saint Martins BA Womenswear pathway. He launched his brand in 2008 with designer Elliott James Frieze, and has been showing on the official men’s fashion week calendar in London and Paris.

He was the crown prince and second son of the ruler of Sharjah in the United Arab Emirates. His elder brother, Sheikh Mohammed bin Sultan bin Mohammed Al Qasimi, died from a drug overdose in 1999 at the age of 24 at the family’s home in East Grinstead in the U.K.

Three days of mourning have been declared in the emirate and flags have been ordered to fly at half mast.

UAE’s Ministry of Presidential Affairs said in a statement that “President His Highness Sheikh Khalifa bin Zayed Al Nahyan mourns with grief and sorrow the death of Sheikh Khalid bin Sultan bin Muhammad Al Qasimi, the son of the Ruler of Sharjah, praying to Allah the Almighty to rest his soul in peace, and grant his family patience and solace.”

Frieze said “I’m shocked and saddened by Khalid’s passing. My thoughts and prayers go out to his entire family and his design team. He lives on in all of us and will never be forgotten.”

Deena Aljuhani Abdulaziz, former editor in chief of Vogue Arabia, said on Instagram, “May you rest in paradise Khalid, you always brought joy to everyone around you and you will be missed.”

Caroline Rush, chief executive officer of British Fashion Council, said “Khalid Qasimi was a talented young designer whose collections were modern, elegant and forward thinking. Our thoughts are with his family, friends and colleagues.”

Tom Van Dorpe, who is a close friend and a stylist to the brand, said on Instagram: “Khalid. I’m heartbroken. I never lost a friend before. You were so gifted, so bright, so kind! What we [built] together was so meaningful! Sending strength to your family and many friends. We lost someone really special. Rest in peace Khalid.”

Most recently, the designer was involved in a controversy with Vetements as the brand featured a T-shirt that read “Don’t shoot” in Arabic, French and English, in its spring 2020 show collection in Paris. The T-shirt is a semi-replica of one originally worn by journalists in Lebanon during the Israeli invasion of the country in 1982. Qasimi showcased his own replica of the T-shirt in 2018.

“This T-shirt was something very personal to me. We’ve reworked it to highlight issues of the Middle East and what’s happening in the Middle East at the moment,” he told Highsnobiety.

The designer showcased his spring 2020 collection in June, where he expressed a sense of hope and positivity to the war-torn Middle East.