Prada has always been a brand that dictates the rest of fashion. That tradition was stepped up in Milan on Sunday with a groundbreaking announcement at the brand’s headquarters. Designer Raf Simons is to work alongside Miuccia Prada. The two will be co-creative directors.

They are two of the most influential designers in fashion, which makes this an unprecedented alpha alliance – the fashion equivalent of Pep Guardiola and Jürgen Klopp teaming up to manage Barcelona, or Bruce Springsteen and Madonna forming a supergroup. As CEO Patrizio Bertelli said through an interpreter in his introduction to the duo: “Here, again, the Prada Group have proven to be at the forefront of change.”

Simons and Prada looked relaxed in each other’s company as they explained how the partnership – officially coming into effect on 2 April – will work. “When we both believe in it [an idea], we’re going to do it,” Simons said. “When one doesn’t believe in it, we won’t do it.”

“We like each other, we respect each other, we will see where that takes us,” said Prada. Simons will live between Antwerp, where his eponymous label is based, and Milan, to work on Prada. The first official Prada-Simons collection will be shown in September.

Prada is now 70 and in her 42nd year designing for the company founded by her grandfather in 1913. She was clear, however, this was not a first move towards her retirement, with Simons in position to eventually take over. “Absolutely not,” she said. “I like working and this way I will work a bit more … I anticipate more discussion, more ideas.”

Simons spoke at length about how their alliance was partly prompted by what he sees as the sidelining of creativity in fashion. “A business can do super, super good [now] without having creatives or, to add to that, without strong creatives,” he said. “It’s not the main reason we are doing this, but we do believe collaborating between creatives can reposition, also, that aspect of the whole business.”

Simons and Prada have known each other since around 2005, when Simons was appointed the creative director of Jil Sander, then owned by the Prada Group. They have remained friends since, and hinted that similar alliances have come close in the past. During a conversation between the two designers published by System magazine in 2016, Prada said: “One thing I would really love to do is to work with Raf, and maybe with other people – it would be so much fun.”

The Prada autumn/winter 2020 womenswear show in Milan last week. Photograph: Alberto Moncada/PR

The duo share an ability to draw on culture, politics and art to make fashion that is thoughtful without being too serious. Designing pretty clothes for the sake of pretty clothes is not something either of these designers are interested in. If Prada’s Instagram bio reads “thinking fashion since 1913”, Simons has said “I don’t want to show clothes, I want to show my attitude, my past, present and future.”

Although they broadly agree on a point of view, they come from different places – a factor that makes a co-designed collection an intriguing idea. Belgian-born Simons, 52, began his career as a furniture designer and is regularly inspired by club and street culture, with menswear a strong suit. Since founding his own label in 1995, he has shown himself to be versatile, having worked as creative director at Jil Sander, Christian Dior and Calvin Klein. Prada, meanwhile, was born in Milan, studied for a PhD in political science in the 70s, and was active in the Italian communist party and women’s rights groups. She has since made her feminism – and the lives of women – a key theme in the way she designs.

Simons joins the firm at an interesting time. Recently, there have been a few more struggles, both financially and politically. Prada was embroiled in a race row in 2018, thanks to figurines that resembled blackface in their New York store. It was announced earlier this month it had reach a settlement with NYC Commission on Human Rights, agreeing to give all staff in the city diversity training, and the appointment of a diversity and inclusion officer to vet all designs. This announcement is perhaps the mark of a new era, an alliance for perpetuity. “The contract is forever,” said Prada.