The lipid bilayer is highly resilient to rupture and explains why it was selected over the course of evolution to serve a barrier function. Yet, fission or the splitting of a membrane compartment is a central theme in biology that manifests during cell division, synaptic transmission, vesicular transport and organelle biogenesis. Fission involves the local application of curvature stress to constrict a membrane tube. Since this topological transformation requires the bilayer to deviate from its preferred planar configuration, membrane fission is an energetically unfavourable process. Using a facile and robust membrane assay developed in the lab, we have elucidated the functional basis for specific proteins that catalyse this process. My talk will describe these recent developments.