When Karl Birkenstock presented the first sandal in 1963 at the Dusseldorf trade fair, people laughed at him. “Fashion at the time was about creating the perfect look,” Birkenstock’s chief communications officer, Jochen Gutzy, explains. Birkenstock’s orthopaedic footwear was in a different lane to the effortlessly chic stiletto heel.

Birkenstock might still pride itself on being functional, but its range of sandals and clogs is finally ‘in’. Its footwear has acquired a cult following in the fashion industry by supermodels and influencers as the ‘ugly’ shoe craze blew up. The Arizona sandal even featured at the crux of the box office hit Barbie, as the existential doll faces a choice between her regular life (pink stiletto) or the truth about the universe (Birkenstock), resulting in a 340% surge in demand for the soothsaying sandals.

The demand for its shoes has propelled the brand to achieve the highest quarterly sales in its history after it was listed on the US stock market in October for $7.5bn (total sales rose 19% to €565m in the three months up to June 30).