Nature Astronomy, Published online: 05 August 2026; doi:10.1038/s41550-026-02948-w Combining galaxy kinematics with a reconstruction of the primordial density field has enabled the detection of a substantial imprint of primordial tidal torques in present-day galaxy spins. This strengthens evidence that the angular momentum of galaxies originates from large-scale tidal forces on their proto-halos at very early times.