The appointment of Amy Lamé as London’s Night Czar in 2016 has focused the attention of policy-makers, politicians and academics, among others, not only on the significance of the night-time economy, in the 24/7 society we are said to inhabit, but on the politics of the city, and its commercial and non-commercial spaces, after dark. This research strand brings together all those with an interest in the distinct ecology of cities at night, in order to explore from a historically informed perspective, as well as one shaped by a comparative geography, the various ways in which, after nightfall, we use and abuse the urban environment.