It’s not what you’d expect to see housed within the neoclassical architecture of Liverpool’s Walker Art Gallery. Ascend its curving staircase, the walls of which are adorned with gold-framed works of art from across the centuries, and at the summit you will see … erm, a zip-up Fila tracksuit top paired with some Lee jeans circa 1983.

This blue trackie sits alongside other prize pieces: Aquascutum scarves, Stone Island jackets, the odd hooded mannequin that looks like it might steal your dinner money. These treasures occupy the opening room of Art of the Terraces which, as you may have guessed, is not the Walker’s usual fare. Timed for the World Cup, it’s an exhibition that aims to tell the story of football casuals – the name given to a generation of fans who, inspired by the rival followers they encountered on European away days, ditched their flared cords and parkas and began dressing in the latest foreign labels.

Their influence on fashion helped turn athleisure wear into a gigantic global industry: before Liverpool and Manchester United fans started wearing Adidas Forest Hills trainers to games, trainers were only really seen on the track. But this is not simply an exhibition of retro sportswear. The casuals had a huge impact on arts and culture too, from former casuals-turned-artists such as Mark Leckey (whose 1999…