LONDON — Stella McCartney traveled to Windsor Castle on Tuesday to see fellow environmental activist and friend King Charles III and to pick up her latest honor, a Commander of the Order of the British Empire, or CBE, for services to fashion and sustainability.

McCartney was among more than 1,000 members of the British public to receive an official accolade from Queen Elizabeth II in what was to become the monarch’s final annual Birthday Honors list, released ahead of her Platinum Jubilee celebrations last summer.

For the investiture ceremony, McCartney donned a custom, tailored navy dress handmade in her London atelier from Nativa traceable and regenerative wool. Nativa’s wool complies with the highest levels of animal welfare, environmental protection and care for farmers and local communities, according to McCartney’s company.

The designer finished off the look with navy satin pumps from her brand’s archive and a clutch from the Stella McCartney Collection. Both were made from vegan materials, down to the glue, the company said.

British milliner Emily-London created McCartney’s custom lace black dotted veil.

McCartney said she was “humbled” to be recognized for her mission to bring sustainability to fashion. “This is such a proud and emotional day for me — not only to receive this incredible accolade from King Charles III, but also to have been included in Her Majesty Queen Elizabeth II’s final Birthday Honors.”

The CBE was honor number two for McCartney. She received her OBE, or Order of the British Empire award, from the queen at Buckingham Palace in 2013.

The designer has worked frequently with Prince Charles on environmental projects and in 2021 represented the fashion industry at the G7 summit in Cornwall, England.

Ahead of the summit, the king (then Prince Charles) gathered some of the most powerful chief executive officers and company heads, including McCartney, to meet with world leaders and demand “coordinated action to tackle climate change.”

King Charles’ group is known as Coalition of the Willing and the leaders involved manage a total of $60 trillion.

“My goal is to drive change, encourage investments and create lasting difference through incentives supporting the next generation,” McCartney said at the time.

“I hope the G7 Summit will translate our message into policies bringing us closer to creating a cruelty-free society that is kinder to all creatures, Mother Earth and each other,” she added.

The Cornwall G7 was the first time that CEOs were able to have official face-to-face meetings with world leaders to discuss sustainability.

Encouraging collaboration between governments and business has long been a priority for King Charles, who spent two years creating the Coalition of the Willing and working with members to develop a series of initiatives to tackle climate change.

The group presented three key initiatives to global leaders, including plans to drive private financing to sustainability projects; recommendations for potential government policy, and suggestions for coalitions to drive change for some of the world’s most polluting industries, fashion and textiles included.

Later in 2021, at COP26, the United Nations Climate Conference in Glasgow, Scotland, McCartney met Prince Charles again. She gave him a guided tour of her sustainable fashion installation at the Kelvingrove Art Gallery and Museum during the international summit.