The main achievements of the ESO key programme on supernovae are presented. On the observational side, the programme has allowed the accumulation of an archive of spectroscopic and photometric data on supernovae of all types. Modelling work has been very active within the programme, and has been devoted mostly to spectral modelling. Early and late time spectra of both supernovae of Type II (SN 1987A) and Ia (SN 1990N, 1986G) have been successfully modelled, with considerable gain of insight into the properties of these objects. The light curve of SN 1987A has also been successfully modelled assuming a ⁵⁷Co/⁵⁶Co ratio of 1.5* solar, confirmed by gamma -ray observations.