Barrel pants first emerged as a fashion silhouette around the 1920s and have their antecedents in riding pants and work pants, but their current popularity can be traced to 2023 and Pieter Mulier’s introduction of Alaïa barrel jeans in his fall collection. Those pants were joined a few months later by the barrel pants in Phoebe Philo’s first namesake collection. Voilà — phenomenon.